Well now I have to update my previous post!
Just picked up a High Standard Sentinel R-100 yesterday from my favorite LGS. Near as I can tell, it was made in 1955 or so. Has a 4" barrel and chambers 9 rounds of rompin stompin 22s! Finish is a little rough but the bore is bright and it locks up tight.
I got this as a fun plinker to go with my Ruger Mark III 22/45. Put in several spent casings and it showed a good strike and a fairly smooth DA pull.
Can't wait to hit the range for some 22 madness!