Awesome job on the dove-tails. I built a bunch of rifle scope mounts for some Red Dot's (vintage, before the turn of the century lever guns) last winter but went the easy route and used a length of Picatinny rail that I had and cut it to lengths about the same as you show.
I thought about making the dovetail bases as you did but eventually decided that $20 worth of Pickatiny was the way to go.
Weaver does make a "barrel pinch " scope mount for pistols but they aren't readily available in this country because "no handgun hunting" limits their usage.