Patrick,
You've passed along what I believe to be one of the best definitions of 'Preoccupation' that I've stumbled across...
Preoccupation:
collectors of US rifles who agonize over whether a particular subsidiary component such as a barrel band is the "correct" one for Wednesday afternoon on the 10th of Octebruary 1944
AH HA
That nails it down to the barrel band being made on the 'Afternoon Shift' 10th Oct 44
Now just need to find which station and who was working the required machinery!
Cheers,
Charlie-Painter777