I can't compare to any of my pistols because I'm still at work, but I'm comparing this to the photos on Karl Karash's photo cd. (If you don't have it... you should!) Serial 9240XX has a similar wheel. Serial 9311XX appears to not have a wheel. Serial 9330XX appears to have a similar wheel. And serial 9332XX has a similar wheel. I'd say you are fine with yours.
The finish on the pistol is near surely original. Surely nobody would add one to an original finish. The ordnance stamp is very weak on most Colts. Looks like a nice pistol. The sear pin is noticeable.
I don't see anything wrong with that pistol... aside from the reversed sear pin. Also somebody at one time used a hammer and/or punch to remove the slide stop, so double-check that it isn't bent or deformed and that the slide/receiver wasn't damaged beyond what we see either.
I've seen a few, but not many. There were actually two sizes used, the large one seen here and a smaller one. The smaller one is more often seen stamped perfectly with all details visible. The larger one would've been much more difficult to stamp perfectly square with the receiver and show all the detail.
The damage around the end of the slide stop pin is fairly often seen and indicates the person doing the work forgot to remove the empty magazine before trying to take the gun apart and lost his temper.
Unfortunately mine is that way as well. Somebody who apparently didn't know how to remove the slide stop simply locked the slide back and started pounding on it with a hammer. He buggered both the slide and receiver somewhat, but fortunately he stopped and finally figured it out before the damage got too bad.