If your hammer can be repaired that would be my first choice. Unmatched hammers look bad. An old gunsmith I used years ago, had many pairs of hammers. Often he would replace both at the same time. Had to weld them to redo the axle hole and time them. I’m sure some went right on but doubt most did. Replacing the pair made the wear and engraving equal on both hammers.
I spent several years trying to find a hammer for a Lang which was mismatched poorly before I bought the gun. In the end i bought a stock, action and fore end of holts. I had them just ship me the side plates with hammers, the trigger guard and the forend. Barrels needed sleeving and the action was well worn. I used the pair of hammers to replace both hammers to get my Lang back to being a shooter. Had to keep the original screws. I have bought 50-60 hammers off EBay trying to find matches. Maybe one in ten work. Now I only buy matched pairs as they make replacement simpler. Well I buy them. Most likely they will never get used like the barrels I have picked up over the years.
