TBH of the top of my head I dont know ,but a half hour trawl through the RS components catalouge (sp) and im sure i could find something, theres about a bazillion miniture non latching switches out there, a countersunk frame with a halo PCB style switch mounted on the inside with the button protruding through to the outside kinda thing ...not saying that specifically would be easy to mount but you see where im coming from?
BTW i hope you dont think im being critical,thats not what i mean im just a nosey ******* and i like pissing about with things too..especially markers