Thank you Ron, I re-read the thread. Being very much a novice, some simple points, from time to time, may seem overly important to me. The last few posts here have helped me come to this theory...
The four knives ordered by the Lt. probably all had stag handles, 3 finger grips, teardrop quillion, relief forward of spine to accommodate the forefinger.

The knife in Gaddis, referred to as one of the first 10, was not ordered by Lt . Zacharias, but made immediately after his order for 4 knives was completed. It incorporates practical improvements as Bo saw them.

The leather handled pre RWB spacer knives, like the one Tune acquired at BLADE, are probably the next step in the evolution of the model 1. (I was curious if any leathered knives were known with three finger grips.)

I'm just wondering outloud!