Entity Michael aka ECHO spoke thus:
> Now, to what I am asking... Anyone have the rough dimensions for
> the rear matress in a 1980 or such years? Mine is missing and
> deciding to make my own. Thank you kindly.
> 
> Michael

I posted  a while ago on the best homemade mattress, too bad the Gerry
archive search seems nonfunctioning so I will rewrite it here:

I bought the LARGE sheet of SS(SuperSoft, due to some physical ailments)
foam in 3 inch thick size. I think it was about 60$. I then cut it in half
and glued the two halves together to make 6 inch, which is soft enough for
me. The upholstery shop will recommend good soft spray glue for this
purpose, it is about 10$.
I then purchased a large VELUX� synthetic velour blanket from Wal-Mart for
36$. After trimming the foam (any sharp knife will do), I cut the velour to
size and wrapped and glued the material to the foam. This material is
elastic and perfect for covering the foam. Try to mask the overspray since
it will attract dirt and look permanently grungy. Folding over the corners
are a challenge. This is a 4 handed job, you will need a helper.
The result is wonderful, the mattress is easy to handle, durable,
comfortable and fits just right. I use crocodile clips and mini bungy cords
to hold the sheet on at the corners since the nonstandard size precludes the
use of mass produced sheets.
This I am sure is the best solution for upholstery ever, NO SEWING!!!!!
Good luck, ask more for tips.

Rachel http://www.gnarlodious.com