Zipadee Doodar wrote:
I have inherited a reasonably large corner bath which has a "mahogany"
panel. Mrs Doodar would like to replace it with a moulded acrylic job, but
local suppliers all say that it is impossible to obtain such a thing for a
bath several years old. (The radius varies from 54 inches at each edge to 60
inches in the middle.)

It's relatively easy to do.
Take the mahogany panel, drill some holes in it, place on vacuum table,
put an acrylic sheet heated to the right temperauture over it, supported
in a frame, and turn on vacuum table.
Wait a few minutes, remove acrylic panel, and you'r done.

Course, without the equipment it's a little tricky.

Could you modify it so that it has a constant radius?
A bit of acrylic sheet bent into a cylinder may work.