As above I need some info on reshelling my classic because its not in the best condition and iv found a sport in immaculate condition, right the engine part I know is the easy part I can fit that with no problem but how hard is it to do the electrics because im no good with that part 

take photos and label every connection - masking tape and a sharpie.

Take your time and you will have no issues, take the opportunity to clean / beef up all the earth points / leads

Is the wiring loom just a straight swap or is there more to it 

I dont know but I would guess you will be changing it along with the engine - but if you are going to the trouble of completing a reshell I would be doing a ground up job so you will have no problem with access etc plus good opportunity to get in there with underseal and waxoil products around seams etc