I nearly viewed this car 3 months ago.... I rang up about it but the guy wasn't in the office so was unable to provide details of the service history, and didn't know off the top of his head about belt changes... Exhaust is aftermarket but he didn't know what brand. It went up for sale in December I think, originally priced at £3700. Seemed like a genuine car to me but I wanted cup packs.
My concern would be that it's fine if you could get a couple of hundred off it as the chances are you would still need to spend out a fair bit bringing it back up to scratch (if the belts have not been done/done correctly). But for arguments sake I would maybe say that you'd be better off putting that money elsewhere. There are lots in good condition with good history that come up for sale on here/pistonheads around the 4K mark.
I don't mean to put you off if that is what you want and I have no experience of the company so can't say a bad word against them. However this is just my opinion coming from someone who had to spend a fair bit on my 182 as soon as I got it, because I was probably a tad impatient...(Hindsight would have been a wonderful thing)