The ice pick sharp firing pin was the first thing to get my attn when I fired my OpenTop the first time.
It would pierce the primers on most every round. So a carfull shortening and then rounding of the tip took care of that.

The loading gate opened a little stiffly, so I took the gate out and reshaped the cam surface the spring slides over during opening and closing and polished it till it worked easier.

The ejector rod would hang up right as you first pulled it back. It has to go around 2 corners sort-of before traveling straight back to eject the case.
Gently angling those corners in the channel of the ejector tube ended that problem.

I replaced the very heavy factory bolt/trigger spring in mine. It was so heavy it was pulling the bolt off the trigger cam prematurely.
I simply replaced with a spring wire sub sold for SASS shooters. I got it from Brownells, can't recall the name. Just a drop in part.
Made all the difference in smoothing out the action and improving the trigger pull.

The cylinder arbor on mine was OK as is.
I've fix up a few C&B revolvers with a shim on the end of the arbor.
I simply soft solder a suitible thickness of steel stock to the end of the arbor. Then trim it round and then final fit it to get the best fit.
No drilling of the arbor or other machining. Just a soft soldered blank on the end. Even brass would work OK if it's final fitted well.
They hold up just fine as there is no rotational or side stress on the tip. It just sits there and the bbl comes back and sets against it maintaining cyl gap..

Other than a previous owner using what appeared to be a rock to remove the wedge at one point, the revolver is in quite nice condition.
Shoots beautifully.
I may pull the trigger out and straighten it just a little. It feels a little uncomfortable as it is,, like it's got too much curve to it.
Maybe just my gnarly fingers, but I still think a slight gentle adjustment will help.
Maybe while it's apart I'll pretty it up a bit. That'll make the Fred Flintstone wedge removal method mark go away.

All that for a $200 repop revolver...