I just finished a conversion on an old Dixie Gun Works flintlock that had such bad geometry that it wasn't worth trying to make work as a flinter. I sawed off the pan, but left the flash fence. I plugged the extra holes with a piece of scrap copper ground wire, that fit pretty well, and hammered a nice head on the outside, but did a shallow countersink on the inside, so I could file it flush after hammering. I wanted it to look like a field conversion, rather than a smith made one. It turned out pretty well. I also added some new made cap erosion with some cold blue,and some bleach, which came out pretty well also. What ever you do if you use the bluing and bleach don't breath it.
Hungry Horse