What you have is a Single-Six 22 LR only, Catalog # RSS5 (5 1/2"barrel), a very early type 1 round gate. The grips are aftermarket and should be black hard rubber. There were 56,000 type 1 round gates made so it's not rare. The gun shows considerable wear so assuming it is in good working condition and has not had the transfer bar modification, it should be worth about $300 at most …. most likely $250.
Age alone is not a big value determining factor …. it's mostly condition an scarcity.
Here's my type 1 round gate RSS5 1958 vintage Single-Six in like new condition: