Late reply. From the picture it looks like that rib has an adjustable front sight. If it does the rib, at least, is not from the ‘60s. The adjustable front sight did no make an appearance Until the mid ‘70s. Looks like a 1390 gun, 1400 being possible score from that time period. I have shot about a bizillon rounds through guns like that.I took some time this morning from chores, and went down behind the barn. I took a partial box of my reloads, 40 total.
I shot 3 targets, 12 rounds on the first two, and 16 rounds on the third.
I'm showing only the third, and best, target. 16 shots, 7 yds. standing, 2 hands.
View attachment 135928
I learned several things.
First - this revolver is meant to shoot double-action.
Second - the trigger stroke should be a complete, smooth, all the way thru stroke. Trying to 'stage' the break makes things much, much worse.
Third - I will probably never shoot to this revolvers' potential.
An interesting feature - the old-style brazed trigger stop. You can see it somewhat in the above pic.
Better pic here
View attachment 135929