Congrats on your gun. Love them oldies. Wish I could find a decent one myself, but they are scarce around here in decent shape.
I have had like 3 of the "Sentinel" Models which look more like stnadrd DA revolvers. One was a Sears/Higgins 88 made by High Standard, a model R-105, and a Sentinel Snub in nickle with dthe mutha'o pimp grips. Killed a javelina with the R-105 at about 40 yds. It was deadly accurate.
Some say the frames for the western style and the stentinels are similar to the point of being almost alike. Suppose to have grip frames that will fit any receiver for either model, but I have never seen enough of them close enough to tell. The cylinders are all nine shot and look the same as well as the crane assembly. All are DA/SA.
As a grade school kid in the 60s, I watched my uncles shoot one "Double Nine" which is similar to the "Hombre." It was a nice nickle one with the white grips. He got it after he returned from the Korean War. He later promised it to me along with my grandfather's 1917 captured Luger if I got him a vintage Colt Ace .22. Well, that never happened. Think I have only seen 1or 2 in all my years of trading and couldn't afford them.
A little history on the Sentinel model I found, not muchon the western models.
http://unblinkingeye.com/Guns/Sentinel/sentinel.html