I agree with Path, i use Manton locks on any 13/16 or smaller barrel that requires an English lock. Grind off the tail and it becomes an small late Ketland as well. Your only other choices are: small Siler, not a good choice due to reliablity issues, Chambers small english round face, if your build needs a 1730ish lock. Now that's a nice little lock! Note: the RE Davis small Siler lock works well.