According to one source, pinned pommels were very short lived in late 1970-mid '71. They were an experiment to do away with the outside tang nut. Shortly thereafter, late '71 or so, the shop reportedly transitioned to the inverted tang nut to secure the pommel, and continued that method... even today. If the source is accurate, your knife may be relatively uncommon (not many pinned pommels were made), and definitely dated to about 1971.

Furthermore, the "7 spacer rule" does not apparently apply to Bowies ... even little bears (?). Few if any Bowies ever had 7 spacers. Note: I've only seen a picture of one other pinned pommel Randall. One was for sale on E-Bay a few months ago...

(Edit-add): Re: Bowies and spacers. I put a question mark after the comment about little bears above because I didn't know if they were assembled in the separate Bowie facility, thus were treated as another "real" Bowie.

After some extensive searching, I found a couple of what appear to be 1960s looking "Little Bear Bowies" with the 7-spacer configuration, one handled with micarta and one with what looks like walnut... no ivory handles however. This would seem to indicate that at least early on, the Little Bears were assembled as per the non-Bowie knives.

The Little Bear was apparently introduced about 1966-67. It hasn't received much attention in the standard reference books nor are there many early examples pictured in discussions. I'm going to keep an open mind about the Little Bears ... could be an interesting research project - did they have 7-spacers? what handles? and when did they quit using that arrangement.)