I'm sorry for the delay, but work was hectic this week. I tried a single six, blackhawk and a super blackhawk and none of them fit the way they should. The grips are too short to fit a bisley and the top isn't inletted right for the normal plow handle frame on my blackhawk/super blackhawk. So, still no idea what these are meant for.....
Gotta admit though, they do look an awful lot like those bisley grips around the top of the frame... could they be for a shorter bisley or maybe a colt frame. Don't have any ponies, so I can't test that one.