The breeches should be pulled, so a good HARD look at the condition and depth of pitting can be surmised. A good 90 degree bore scope would be even better.

If Ok, I would most certainly do a restoration attempt.

Not sure why it is so beat up on the muzzles, but what the hay - it's certainly re-crownable.

Emery and a coned piece of wood (or emery around a tapered stone - rotated in the muzzle), then the end of your thumb will do a splendid job.