Have you seen
http://www.screwfix.com/app/sfd/cat/...14491&ts=87967


I have now, thanks. I assume it does not have the same destructive powers
of silicone sealant, since it is meant for mirrors.

In another NG, they suggested panel pins. I would think I would have to put
a sheet of cardboard between for that, so I don't get a scratched mirror
over time.

Bob