For a while I also had automated searches running on e Bay for these 14 amp types - whenever one appeared for sale I would contact the seller, asking for the serial number.
9 out of 10 did - many thanks to them for their trouble and good will.
Fender never replied, and the magazine showed polite disinterest.
I'm guessing amp-owners like to know when their amp was made, if it's old-ish.
I run a couple of websites making the schematics for these amps easily accessible.
As people download them, I'm hoping they'll respond to my request that they send me their amp's serial number for this project, and many do.
Subtract one from the other and I'll have a rough-cut figure for how many were made. PRII owners were kind enough to start sending their serial numbers in.
I was puzzled to see how some of them were separated by over 100,000.
It represents fourteen years of hobby time, so if you quote it elsewhere, I'd appreciate a link and/or a name-check, either as "Stratopastor" or under my real name.