Thanks piper, but I'm thinking of one that I can leave attached to the rail and just slide the rigger in to the mount with out having to tighten any screws(like the cannon mount). He has the ones you've got pictured.

I'm thinking my machinists buddy is gonna end up making them for him, but maybe there's something in production out there.
_________________________
There's no head like steelhead!
Operations manager of coors light testing facility.