One buddy just got in touch and told me he thinks your neck was stamped with a smaller stamp that was more commonly used on guitar necks... he said the 02 was also used as a code for "maple" and you see it more on guitars... and that the divider mark in the middle of the neck identifier and the date code was more commonly found on the smaller guitar neck stamps used.
So, your neck code breaks down as:
01 - Precision Neck
02 - Maple
03 - 3rd Week
9 - 1979
1 - Monday (is that a 1? It's hard to read)
He did point out that it's not common to see a guitar neck stamp on a bass neck, but that it's nothing totally out of the ordinary... the guy probably just grabbed a stamp off a guitar bench and stamped all the necks that were made that day. The 70's were like that... very inconsistent.
So, if he's right (I believe he is), then I must have been misinformed previously... I swear I read it somewhere, but we all know how that goes.
If my other buddy pulls through with something different, I'll let you know.