Thanks for all of the responses guys. It's some good stuff to think about.
I'm guessing my compass wouldn't work with the SK7 mount from DSS.
It absolutely will not work.
It is not just the fit into the boot. The floating part of the compass of an SK7 has a
tiny protrusion on it that fits into a
tiny groove on the inside of the bezel. The bezel has a
tiny protrusion in its base that fits into a
tiny groove on the mount. Without all these things in alignment, turning the top part of the bezel turns the bottom part of the bezel, the floating center, or both. This makes the compass of no value.
I emphasize the word
tiny because not only must things align, the mount must be very, very tight fitting, or the protrusion in the bezel will just slip out of the groove on the mount when you try to turn it. The bezel can even slide right out of the mount.
Believe me, I know. I recently loaned my compass to someone, and the bezel came off underwater and was lost. I got a replacement, and a whole group of us tried repeatedly to get it back in place so it would not slip. I could not get it right. I left it for a week in frustration, and then I tried to work on it again and saw that it seems to be OK. My theory is that the mount was beaten up and stretched by all the work we did and slowly came back to shape over time.
During that week I met someone else with a DSS mount, and he has had the bezel fall out several times. He also says it sometimes slips while he is trying to use it.
In retrospect, I think I would try to thread the bungees through the wrist strap slot if I had it to do over again. The original Suunto mount is extremely tight.