Terrific knife, Toby! Actually, Robert Clemente does mention the early bird's head in his description of the 171UH: "... the very first production units up until 1973 had a unique handle...". The thing is, just like I didn't know until Larry showed me a pic of one, that it was a bird's head pommel that made it unique.
I have a couple of these, one is a user grade, that I had Paul make a sheath for. Both are what I call the 'Signature' issues, as they have the recessed, pebble finished area on the front of the guard, with 'Uncle Henry' signed in the usual script., the serial numbr on the other side. On the 'user', the tang markings are stamped in, very deep. On my other 171, which is near mint in the box, the tang markings are etched... as is the 'Schrade Super Sharp' on the blade. I wonder how many little nuances there are within the total 2 production runs of this knife?
Phil