you got a hell of a deal! .1:48 with the 50cal and 1:66 with the .54cal

for the 54 try 70gr pyrodex RS or Black powder, .015 patch and a .530 round ball.

Contact CVA with the question about converting it over to flintlock. You can get the CVA lock on ebay or gunbroker for around $30 and if it doesnt spark i can hook you up with a guy that rehardens frizzens for $20. He does a damn good job too.