Seconded

The single digit OMs are much nicer than the double digit models.

I am guessing, but I suspect it won't be the shoe itself, but whatever makes the connection when the flash fires, prob deep in the innards. Mike spencer at camerarepairs-r-us dot co dot uk will probably be able to help, if necessary. I send my OMs to him for fettling. Personally, I wouldn't bother paying to get an OM10 fixed though. Just buy another they are so cheap.