My dilemma, if you are able and kind enough to help me is this:

I really like this man that for a long time, used to mock me with his other friends and I just used to ignore it. I am an educated, emotionally intelligent and Ingrid Bergman attractive although with sophia loren eyes, so I am pretty attractive physically, though have naturally large breasts I am very self-conscious of but show with confidence to the man I like.

Large breasts tend to be a distraction for men, you want him looking into your eyes most of the time, not at your breasts.  Yes, it is good for him to have a sneaky look at your breasts every now and then, but you don't want him focused on them all the time.  If you want to have a more positive affect on men, try to make your breasts look smaller, so he still likes the look of them but is not constantly thinking "look at the size of those beauties".

I am pretty sure he likes me and we seem to glare at each other quite a lot. I do anything he generally asks of for a favour and we stick up for each other when we need. There is a lot of positive body language.

Good, it seems he has some sort of interest in you.

However, he has tried quite a few times to get his friends interested in me too and they have tried to cross boundaries with me I have been assertive and never allowed either myself or them to come near me when clearly and my love-interest knows that I have never fancied his friends in the slightest (they are builders).

This, seems a bit suspicous to me.  Why would he fancy you, yet try to get his friends interested in you.  It seems like a game is being played here.  Men don't like any competition to get too close to the women they fancy.  Whilst he would be proud that lots of other men would fancy his woman, he wouldn't actively try and tout for competition.  Sounds as though they are playing a game of "see if we can get this woman into bed, and maybe even see how many of us can get her to have sex with us".

One of his friends got my number from him one night and kept texting me. I only knew him from when I used to live in another house he did some painting there but there was never any indication that he liked me. Then this night, called me up out of the blue and said he was coming to have sex with me!

Absolute sicko, he and possibly all the others are using you as a sex object or game.  You just don't say anything at all like that to a lady you fancy.  In fact I personally wouldn't be sick enough to say that to a woman I didn't fancy either.  It is just plain creepy.  I know guys hear a lot, that women like assertive, pushy, bad boy men.  I don't know how true this is, because I'm not a woman, but this guy is definitely going too far.

I was so shocked by his saying this that I kind of was engaging in the conversation to ascertain if my love-interest had gotten him to do this and why?

If he did, then he is a sicko too.  But this kind of defies belief.  Maybe this has worked for other women in the past.  But to me, this is just disgusting behaviour.

Then he turned up and I had to get the police out on him for trying to get into the house.

Good job you got the police, because he sounds like a sex pest.

I never spoke to the guy I like about this and felt that I had dealt with the situation very well and didn't want to make any assumptions.

It's right not to make assumptions.  But the way I see it is, this guy associates with idiots and even if he was going out with you, would still be associating with the same idiots.  In my opinion, you should stay well away from all of them, including the guy you fancy.  It doesn't sound as though he values you that much anyway and if he can't keep his creepy friends away from you, I don't see the point in going out with him.

But this guy I like is so different when he comes to fix something in the house I rent a room and has grown to be more interested in me and flirts a great deal but we never do more than this.

It maybe that this guy is a good apple, that associates with a load of bad apples.  Nevertheless he will have to find some better friends before he goes out with a woman like you.  Or else ditch his friends and concentrate on you.  If you give him access to your room, it's a wonder he hasn't pushed you into having sex with him yet.

I don't know what he is thinking and if he sits in the pub with his friends laughing and joking about my breasts that have been a topic of converstaion before with him and his friends and him trying to get them interested in me, it just all seems so bizzarre.

You have hit the exact situation with big breasts.  Big breasts are a source of fun for men.  They typically say the same old boring thing over and over again when they see a woman with large breasts ("look at the size of them", "look at the melons on her", "I wouldn't mind sucking on them" etc.).  Big breasts attract a blokes attention everytime, particularly if he is with a group of men.  It's not necessarily a good thing for women, because it immediately puts sex into a blokes mind rather than what you really want, which is a guy that thinks you might be a long term relationship potential.  Of course, some women with big boobs, might want oversexed bloke trying to get off with them all the time (again that I don't know because I'm not a woman and certainly don't have big boobs).

I really do like this man but am worried that his friend had told him that I led him on and got the police out when he turned up.

I wouldn't worry what his friend has said.  If he fancies you and knows how much of an idiot his friend is, I don't think that matters.  Moreover, if he fancies you, he should have given his friend a serious talking to.

I wasn't trying to do this at all, I just was taken aback by the call and content and was wanting to know how on earth he had gotten my number and subtedly wanted to get to the bottom of it and kept asking if my love interest was there with him as they do go out drinking together. He had apparently gone home but the friend had told me that he got my number from john (changed the name for privacy purposes).

Now it appears as if perhaps, I had in some way led him on? - I shouted at him to go home to his wife several times in the phone dialouge and was assertive about where I stood. My love interest doesn't seem changed by it but that I find myself not knowing whether his own intentions towards me are sincere at this stage?

You did the right thing, and I'm sure most women reading this web page will agree you did the right thing by calling the police.  You shouldn't give a stuff about what the guy you fancy thinks, you needed protection at that point, it could have turned out far worse.

We aren't even dating, but the attraction is just evolving and getting more stronger each time he comes around to mend something at the request of the landlord. He trembles and goes red around me and asks me about me as if he is sincere and he often runs up to me unexpectedly and just stops and glares into my face in a frozen stare and beams and smiles intensley the rest of the time.

It sounds as though he is quite nervous around ladies, and definitely not as assertive as his friends (thank goodness).  The fact that he hasn't forced you into having sex or making a move, when he has exclusive access to you in your own house, is a good thing.  Whether he fancies you properly or whether he sees you as a sex object, like his friends, I can't really answer.  Much of what I have said in my replies have been negative about him and his friends, so I would be more inclined to believe this guys interest in you is more sexual, than interested in any relationship.  He is just a little more nervous and subtle about demonstrating than his friends are. 

It maybe that he is just embarrassed by the way his friends treat you,  and lets face it, he could probably defend you from one man, but certainly couldn't defend you from a whole group of his friends.  He would just be fighting a losing battle there.  I somehow doubt that he is trying to get his friends interested in you, it just doesn't seem logical for a bloke to do that.

am I being made a joke of or is he really interested?

It is not often, I say this, but I'm not sure in this case.  On the one hand it sounds as though you have found a genuine guy, in amongst a bunch of idiots.  But I can't say for sure whether this guy would turn out to be the same, if you got to know him. 

"Woman, big boobs, his friends have had no luck, it would be a good catch, if he managed to get with you".

My conclusion would be to find another man.  This guy associates with idiots and those idiots are likely to continue to hassle you, even if he is going out with you.  I can't ascertain whether he really does fancy you.  Or whether he is just a nervous version of them, that wants the sex as well.  It does seem like a game or competition of who can get with this buxom babe.  Though there is also a hint that he fancies you.  But to me a hint is not good enough.