Hi Maria,
Take a look at the following thread on the message board which I posted details of the rear seat assy and pictures of my one fitted:-
http://www.tssc.org.uk/messageboard.asp?board=gt6&...
This will give you an idea of what you actually need. The rear barckets would be easy enough to make up, it's the front ones that support the seat in a
folded position that would b difficult to replicate.