Check here for seat frames, not the best, but all we got ...
http://forum.cgoamn.com/index.php?topic=3820.0Had mine apart (vinyl removed) but didn't want to remove foam to get better measurements, my foam was still good and wasn't going to come off easy, started tearing were it was glued to wood.
I have vinyl seat patterns, but ED is using them now, he is also building seat frames from pictures/measurements at above link and will get better measurements when done.
As soon as he ship's vinyl pattern back, I'll let you know ...
My CV is in my garage, so your welcome to come over and look, and /or take measurements any time.
I found some vinyl under deck that was still in good shape, color wise and used that as a base for my vinyl, came close to original color.
Got my vinyl online after sending for samples, some of the samples that looked close on computer were way off in person.
Do a "Google" search for "pleated marine vinyl" ... bring your sample to local shops to see if they can come close to color.
And look here ...
http://forum.cgoamn.com/index.php?topic=6883.0A friend did my seat backs, seat bottoms and splash well curtain, I was able to do the side pads, looks like you still have the wood in side pads for patterns ...
I got enough to do everything with a little extra in case something went wrong or I got a stain/hole/burn in seat bottom.
Pleated vinyl = 5 yards
Plain vinyl = 4 yards
Piping/welting = 18 yards
Burl wood decal for seat bases ...
http://www.metrorestyling.com/Flexible-Burl-Wood-Woodgrain-Vinyl-Wrap-Film-p/burlwood.htm