My bolsters are factory OEM, but any canvas shop worth their salt could easily replicate them.
Very easy on the knees...
Had mine re-covered about 6 years ago and I was very surprised at how simple they really were.
The backing is simple Starboard (maybe 1/4 or 3/8"), and the foam and covering is attached using stainless staples.
Each panel is equipped with stainless blind nuts, and attached to the washboards from behind with stainless bolts.
As stated, any good local canvas shop could make you a set in no time.
Thanks for the reply's. The SeaDek looks great But I have a 2510 with a closed transom. I think I would have to cut into a few pieces to fit the curves around the fish boxes in the back.