Again, this was almost certainly a proof of concept gun, in which they just took whatever frame was handy and cheap to experiment with.
The frame isn't important, it was the barrel system that was being investigated.
Since the Colt Mark V was made in the mid-80's, they would have been copying Dan Wesson's idea, which came earlier.
Which brings up the question of why S&W hasn't offered something like this with their new two piece barrel guns.
The only real difference is the S&W uses a one piece rifled tube with a flange on the front instead of a nut system.