Hi Josh,
Your lock was made by Pedersoli despite the "Stowe 1776", which was a bicentennial thing. You need to check how deep the slot for the sear spring is. On some Pedersolis the slot is so deep that if you file away the lettering, you will come close to breaking through the lock plate. It is not as easy as filing off the lettering because you have to preserve the curve of the lock plate surface and avoid filing a flat. That means the edges can get very thin. On Pedersolis, I usually file the markings down a bit and then weld them over so as not to create a raised lump of weld. Make sure you use mild steel rod so it does not harden during the welding process.
dave