I have a Military Heritage blunderbuss. I knew it wasn’t the highest quality when I bought it but I thought it might be fun to shoot. Anyway, I can’t get the frizzen to open all the way and the **** therefore doesn’t fall all the way. I’ve polished the frizzen spring as and the part that slides on it. I don’t know the proper name for it. Where might I get a working lock and what do I look for?