Between my eyes, the computer screen, and the angle at which the photo was taken, the serial was unclear. The lister has checked and responded (Thanks, Tom!) that the number is Q2854 and is squarely in the 1972 range. (8 instead of 3, 4 instead of a serifed 1)
heck, there goes my lunch money!
Bob (bike addict) Hillery
Stratham, New Hampshire, US.