I priced up the covers from YearOne, $620. Don't think they use Legendary any more, from what I've read the quality is not as good as it used to be. What with shipping and duty and VAT I would have been looking at close to £600.
The covers I had made are about 3/4" thick, the vinyl on top is laminated to 1/4" of foam, then there's a 10mm layer of foam then a bottom layer of vinyl. I was given three samples with different thickness foam in the middle, 6, 10, or 13mm. The stitches looked the right depth with 10mm so that's the one I went for.
All the foam and the trim underneath the seat is new as well.
Cost me £1000.
1970 Road Runner, 505CI, 4 speed, GV overdrive, 3.91 gears.
11.98 @ 117mph on street tyres