Chuckle....
I toyed with exactly the same idea of ply and glass. but did not even get to the drawing board stage..
My seats are tucked up in the loft, I only bought them to ensure the runners would be mounted in the right place, they will not be back out again till next year.
Same goes for the body, that's being ordered next week, mainly so I can check bonnet clearance. I then have to store it safely till needed...
TT