Nice find! Always liked the 3 screw Rugers and the Flat Tops are just a special variation.

Treat those early black Ruger XR3 grips nicely. Even though there's only one complete panel in the set, they still have some $$ value to Ruger addicts. Finding an odd side to replace one that has broken on their gun is always a challenge. Even the screw & escutcheons are special as is the period Ruger Medallion in the broken panel. The panel can be fixed too as an option.

Looks like a steel ejector rod housing (?) and the early small ejector rod head that they used on the Single Six. Both fixtures on the earlier F/T 357.

I'd bet that's an accurate revolver. 357 can turn in some great long range shooting.

Any thoughts of a 44spcl or other caliber conversion on it?
Steel grip frame, ivory (verified antique of course), engraved, ect.
Must be lots of neighborhood BBQ's to attend around there!
..Or you could just wear it around the house to remind the Mrs. where the Bathroom remodeling money went too.