For what it's worth, an authorized dealer showed me an old model 2 that just had a portion of the little knife part of the stamp on it, the handle actually, and told me that GR told him (and now I'm telling you, making this about 3rd hand info), that back in the day, Bo Randall would send out a knife if there was any portion of a stamp on it recognizable as a Randall stamp.

Possibly a disatisfied customer back in those days might request the etch on such a knife?
I'm just guessing, no need to pile on....