Perhaps a third choice. I will never again buy or use another L&R flintlock. L&R percussion locks will spark a cap. If I was in your shoes, I would buy a Chambers lock, and inlet it to fit. Or, buy the "gunmakers kit"; and file the plate to fit close enough, the inlet.
I have a Dixie lock I could not get parts for, the parts are no longer listed in the catalogue. I sent the lock to Dixie, their gunsmith repaired it, very reasonable price. :applause: