With any builder ask them how early their gun is suppose to represent, then do some homework on time frames for types of locks carving styles types of engraving and such most "early" guns around are probably circa 1775-1780 by default of how and with what they are made, it is worth the time tocheck on what you are getting especialy if you are looking to go pre rev war, always confirm anything any builder proposes/advises there are ,many great builders and many great gun historians but few who are both.