A few years back I chronicled the mods to my cabriolet seats, and it can be found here:
https://www.speedsterowners.com...6#429002478259791936
Beware, that I can say less with more words than most other people this side of Samuel Clemens so it might be a long slog of a read, but it is pretty detailed (and funny, at times) if you wish to tackle that sort of thing.