I had a customer who has limited mobility in his shoulders and a CCW asking me if there is any such holster that would strap a small pistol to his arm and allow him to have some kind of spring loaded release so he can get it quickly. Sounds like a crazy movie stunt to me, but i told him i would check into it. Anyone seen something realistic like this?

There have been some gimickie stuff made over the years, but nothing I would risk my life with.

I would recommend that your friend think about carrying his small handgun, just to the right of his belt buckle if right handed, left of it if left handed.

He can conceal it with a shirt left untucked.

I have carried even a Commander sized 1911 like this many times when working in a crowd, bar, etc. when I needed to conceal/protect, yet have INSTANT access to my primary handgun.
I always used a Milt Sparks IWB holster.

It works great with a short barreled revolver as well.