Used to be a lot of 'em around - -
High Standard made that same basic Sentinel revolver which FPrice illustrated, but with a Colt Single Action Army-style type grip frame and dummy ejector rod tube. I believe the latter housed the cylinder release. At lease one version, with a longer barrel, was called the "Longhorn" model.
These western style variants were mainly novelty revolvers, plinkers mostly, and did not require the rather lengthy process of ejection of empties and insertion of individual rounds through the loading gate.
On the other hand, the four-inch Sentinel was a pretty compact little piece to carry hiking and such, with ammo capacity rivaling the Colt, Ruger, and High Standard autoloaders. H-S also marketed a really nifty version with a two-inch barrel and round butt, as a defensive handgun. It even came with the frame anodized in different colors! THAT was a cute little item, the small caliber notwithstanding. Sorta like a less expensive S&W .22/32 Kit Gun.
I have only fired a few of the Sentinel-type revolvers but they seemed to be sound and well made, good value for the money.
Good luck - -
Johnny