Most of my sight work has been on Italian replica Colt revolvers, the majority cap n ball. If I make a mistake, I haven’t ruined an expensive gun. For windage changes I just widen the notch in the hammer in the appropriate direction. Elevation can be a little more creative. Shooting low is an easy fix, just file the front sight till it’s dead on. Most of them shoot high because the arbor is too short. Fitting that will usually fix the problem and there are many ways to do that from complex (weld material to the end of the arbor, then file to fit) to doing the same thing with washers or JB Weld. However, I’ve still had a few that hit high and I made new front sights. I used a piece of brass rod for an 1851 Navy. Screwed it into the stock hole and filed to correct elevation. I made another front sight for an 1861 Navy from a silver dime. I cut a cresent shaped piece off of it, leaving a nub in the bottom middle that screwed into the stock sight hole. It looked great and I didn’t have to file it, my original guestimate was right on.
I have made factory front sight taller using JB Weld. My early production, Israel made, Desert Eagle being an example. I removed the finish from the top edge of the sight, wrapped it with tape, leaving the top open, and packed in about an 1/8 of an inch JB Weld. When it cured, I removed the tape, cleaned up the sides and reshaped the top with a fine sanding block, then colored it with a black Sharpie. Now it hits dead center on a 50 yard bullseye instead of a foot high.