Flint62, my twin, helped me sort out the issues we had with mine (now he has it to mess with...) which was marked as "EAA". I had to have the frizzen rehardened, the tail of the frizzen reshaped, polished all internals of the lock, filed the back of the lock plate smooth/flat, and we installed a touchhole insert.
All that helped, but I could never get more than 75% reliability and it just took all the FUN out of shooting a rocklock... So I almost quit shooting one...
Finally, at my brother's suggestion, I upgraded to a nicer flintlock (a used JP McCoy) and now I am much happier shooting a flintlock that fires near 100% of the time.
I did learn a lot from all the work and hours spent on that one -- but I hope yours sparks much better than mine did.
For your info, L&R's "Maslin #1" RPL Lock (RPL = "replacement lock") should fit that gun, with just slight modifications for the tail of the lockplate, but I decided not to go that route...
Good luck!
Old No7