And i thought my post count was low for same amount of time. I'm not worthy!!
Randall offered lower price Solingen bladed knives, and was a loser for them as so many required extensive regrind. They continued to put those knives out until well after Vietnam, and a few have turned up of nearly shocking newer vintage.
The engraving, if done opposite side of shop mark, was acid etched per original order, or even added later. I have a Model 1 with my various units listed on it. Having done so does not make it a Vietnam knife, WWII knife, or even owned by someone who has even served. The knife needs to be viewed in light of what handle, possible spacers, sheath, etc, for any possible dating.
The Solingens often bring more than forged Randall of same time frame, which is justice for you. Unless a "fighter", am guessing a #14 or #15.