No...as no part of the back is flat, its the opposite concave (if that makes sense) so only the very outside edge actually touches the seat. Reckon best option will be fit a pad of seat foam so its a flatter surface, fit that to the pad, then fix it to the seat. DB - no its behind my butt not under so would just slide off
You should try this stuff,Black Tiger Seal Tigerseal Adhesive Bond Body kits PU: Amazon.co.uk: Car & Motorbike, and then clamp the pad to the seat,if you cannot clamp the pad why not use some resin and bond some bolts into the pad then glue and bolt in on.
I've used this Tiger seal and it is great stuff. Thick consistency which grips the surfaces so no need to clamp, just press-fit and maybe a bit of masking tape for 24hrs. Only problem will be if you ever need to remove the bum stop since it's tough stuff and will probably break the items rather than relinquish its grip. Rich