Rick- No suggestions here.So many people made their own equipment back then it's hard to say.I've had bows that were not made by Nels Grumley but came from old time Michigan archers that obviously knew him.The bows they made were very similar in many ways to one of Nels' bows but they were obviously not made by him.Similar brush nocks,trapezoidal limbs,finely wrapped leather grip.I imagine they picked Nels' brain a bit back in his workshop at Bear Archery and asked for his help in making a bow,especially if they were novice bowmakers.Kinda like Gary Davis here in Michigan or other talented bowyers,willing to show them some tricks of the trade.The Grenier hinge is a "Detroit" made item so I imagine this bowyer possibly knew the same group of guys such as Nels,Fred,Tracy Stalker,etc...