Roy, never used mink before, but sure is a nice dense fur so I think it should do really well.
Red, I've never tanned a fox hide before. I've done several deer and they turned out ok, not as good as a professional job though. Fox should be a lot easier to work, so I expect it to be fairly easy to get a decent looking job. Don't have to be perfect for silencers any way. I'll let you know how they turn out.