Early on in this lock project, Scott and I talked about double set triggers. Before he sent me the casting set, I bought a left hand tumbler for an L&R lock. The tumbler looked OK and it was cut for a fly. I was disturbed by the fact that the hole for the cock screw was cast in, and in light of a previous post about casting flaws I felt that casting the hole was a bad move. In the end the spring lever was way too far out of line with the cocking notches to be used. The Golcher tumbler is an accurate casting, taken directly from a Golcher original. Anyone who has taken apart old shotgun locks or mid nineteenth century hardware store locks might have noticed that they would never pass Jim Chambers' inspection. These locks were filed, screwed together, hardened and sold. Many Pittsburg percussion locks were sold and used without half cock notches. Having said that, I will also say that These old locks were used and often used hard. The Golcher thumbler didn't have quite enough metal to get the two journal surfaces truly round and concentric. If I were making this lock for myself, I might have pushed a little harder to make it work, but I felt that time, for one thing, was not on my side. The most straightforward solution was a left hand Siler tumbler and mainspring.
In order to make the siler parts work with this lock, I needed to reclock the square hole in the flintcock. I did this by drilling the square hole and threading it for a 7/16" fine thread. I screwed a plug into the hole and cut it off with about one sixteenth standout on both sides of the flint cock. I used the half cock notch and the sear to clock the tumbler and rotated the flint cock to it's proper attitude, making sure that the hammer down position wouldn't lose the mailspring. The rest of the lock pretty much went together with #4 screws and minimal headaches. I did carbon pack harden the frizzen because it is made from 6150 steel. 6150 has manganese and vanadium in it which makes it pretty tough, but not spark hard IMHO. I also water hardened the frizzen.
Overall I would say the Left Hand Golcher is not a beginner lock but it is also not an especially difficult lock to build, especially with the siler tumbler. The Rifle Shoppe Has a small 'v' pan lock with a double throat flint cock which is a little smaller than the Golcher , If you are looking for a right hand Southern lock. It is called the HENRY lock and I put one on a .32 cal. That rifle lights off every time the trigger is pulled. Good luck and have fun.
Clint