I've made one lock from scratch , patterned after a Siler. I just wanted to see if I could do it, and really have no need to make another !! However , I tried using files etc, drill press and a bunch of other things to make a usable tumbler. Never did end up with anything I was really happy with , so changed it out for a Siler tumbler. Now the lock works well. For me that tumbler was the stumbling point. How many gunsmiths made their own locks , and where are all the surviving 18th C tumbler mills ? I believe history tells us that locks were almost 100 % imported during this time, and lock making was a guild bound industry in Europe, with specialists i.e. filers, etc.