Value of Ruger model single six 22 revolver with holster?
Impossible to value with just the information provided. Need finish, condition, box, papers, accessories, etc..
What is the value of a Harrington Richardson Ulta side kick 22 pistol serial U20150 with holster worth?
The Blackhawk was not made in 22 LR. If you have one with "Blackhawk" on the frame, you need to call Ruger. There is an almost astronomical chance that you could have a factory experimental, but, I doubt it. More likely you have a Single Six of some type or maybe a Bear Cat. Any of the 22 revolvers can range from 50-400 depending on specifics.