There is an upcoming auction with 32 blackhawk serial # 650-40678 . The frame is color/cased similar to what h and r rifles and shotguns were. Question is was this a factory gun or was it done after it left Ruger? Thanks !
Serial Number Search, thru Ruger, shows this gun was produced in 2002 as a Ruger SSM-4F-S Model: 06515.
this is more commonly called a Baby Vaquero, w/ short grip frame and it is the Ruger “Color Case“ which was a chemical application,,,,
fyi,,,, that does not hold up very well under use, wears off and dulls. A lot of them get Blued when re-done.
Here is some education & good pictures of this model.