Wow, that old girl has seen some hard times! But it is looking pretty cool now. I think it would be a great candidate for parkerizing or bead blasting.
The rear sight blade with the right side broken off looks exactly like the one on the Model 15 I was issued when I joined the local Sheriff's Office back in 1980. I later became a S&W revolver armorer and found that to be a common occurrence with LE sidearms.
I actually started out my LEO career back in the late 70's with a 6" Model 28 and later switched to a 4" version as it was easier to carry. The finish on both guns got a little worn from being carried, so I had them worked over by F. Bob Chow in S.F. during the early 80's.
I foolishly sold off the 6", but I ended up giving my dad the 4", which he still has....
I had him take it out of the safe recently and saw that had a small bit of rust forming on the rear sight from sitting in a pistol case. I took care of that right away.
I recently found a nice 6" (For $449.95) down at the local shop and brought that home with me:
It came with the rubber grips (Which is exactly what I had on mine back in the day), but I replaced them with the grips that came off my original 6" when I got her back in the 70's....