I have a very old (I estimate 1850's) 15 inch trysquare with a brass nib on the stock - it has two marks on it, one is the initials W G carved large into the wood (obviously an owner, my guess is the original owner) and the name DIXON in small lettering stamped as a single stamp (not made up from multiple punches). I don't think DIXON is the maker, probably a later owner.