MK1 GTI conversion

Hi guys.

I had heard about the MK1 GTI attraction a while ago and decided fairly recently to maybe dip my toe in and I came across a Mk 1 1983 GTI tin top for sale for about £3k. It is MOT expired so I thought maybe that could be about right. BUT, doing a history check it was first registered as a VW Golf C petrol
(I assume this is just a standard small engined Golf?) but had a GTI engine fitted to it later in life. According to the seller this was done before his ownership before 2010 and according to the receipts he has it may well have been done to a high standard. However, other than the engine what is the difference between the Golf C and and GTI. In a way, maybe this is the closest I can get to a solid rot free "GTI" for my budget but I would like to know just exactly what I am compromising e.g. are the bodies identical but only the cosmetics different? Is it literally just the red bumper piping? I realise this is a push asking you folks what a 33 year old Golf C was exactly ! 

Of course, as it wasn't born a GTI the history and value isn't there but assuming it is solid and straight enough body with reasonable engine what would you pay for a "decent" converted GTI?

Cheers very much guys, Jock
 

There's tons different, I've made a fairly long list before so def worth a search.

I've listed everything too somewhere. Some like, engine mount re-weld, gearbox have presumably been changed but other stuff like suspension, brakes, interior etc may not have been. And some like cooling system, wiring, tank and fuel system may have been botched to work.

I'd look for an original if I had £3k. Or an original base 'C' as lots have been butchered to make a pretend GTI !

Thanks for both of your replies. I tried a search but I didn't get on well! Ah well, maybe I will just wait out for a slightly rougher GTI.

Cheers again