Michael,Seriously, many years ago I had an M2 Springfield that was obviously converted to a box magazine fed, .22 Hornet by G&H. The bottom of the receiver was machined in typical G&H fashion to feed, and a new box and follower along a with beautifully finished '03 trigger guard/floor plate were fitted. The stock, sights and scope mounts were all G&H, yet it was not marked G&H. The answer I was given by the gentleman who was running G&H back then was that they only marked firearms that they rebarreled and this one still had an M2 barrel although the rifling and bore diameter were the only vestiges left. Is it possible yours has a Springfield barrel?
This one does have the original Springfield barrel but I have seen many marked G&H's (I have one) with the original Armory barrel.
Unfortunately there is no
RULE why some rifles were not marked.