I've been looking for one of those belt buckle revolvers (with buckle) for years. I've only seen one in person and that was at least 15 years ago.
I used mine to defend against a flash mob, free some hostages, and take a hill.
Ok, I mainly use it to weigh my pocket down. Still love it though.
I saw one in a LGS a couple years ago, the last time I was in that store. It is not really local. I can keep my eyes open if you really want one though.
They sell the belt buckles on the website: North American Arms BBA LR BELT BUCKLE WESTERN