Leather seats

I`m looking for a set of black leather seats to go into my mk1 gti. I know that mk2 gti seats fit straight in but what other models have seats that fit?.  Was the leather standard on all mk1 gti`s if not which one came with it?.  Would it be hard to modify newer vw leather seats to fit?  Any help appreciated, cheers.

Hiya m8 dont know if you seen the thread i put in the for sale section under campign,but the leather in the car i think he will sell seperately as he has the original as well his tel no is in the thread and pics of the leather good luck m8.