AH HA- you may be on to something here Jim! I've now seen the "B" regulator with the silver label stamp linked to 1962 Ford Trucks and 1962 Fairlanes. I also just came across a page out of a Thunderbird online restoration guide that showed the original voltage regulator for a 1962 T-Bird, 35 amp is a C2AF-10505-B but doesn't state what color the label stamping is (assuming silver like all the reproductions I've seen).
Found out too that Fabulous Fords sells a Silver Voltage Regulator Decal for Ford Part #C2AF-10505-A for "Early 1962" cars and ALSO sell a blue one for the same part # for "Late 1962-63" cars (and obviously 64 Mustangs with generators) so the "A" version in fact had both color stampings on them. This makes sense, since I know they used a lot of parts from other Ford cars on Mustangs in those first 6 months of production.
This also clears up why the 2nd digit on this part is a "C2XX" (for 1962) instead of a "C4XX" (for 1964) which most of my other parts have on them, but it's starting to make sense. Here's my theory after researching this for WAY too long now-
C2AF-10505-A- original/correct stock regulator for the 64 1/2 V8 with generator that came with BOTH blue AND silver label stampings on them. It was also used on other "late" 1962 and 1963 Ford cars, and they probably used these "extra" ones on the early year Mustangs, then changed to a C5XX regulator after 12/1/64. AMK made the reproductions with the blue stamp but this one is not listed on their website anymore, and 3 other Mustang places I called are out of them (and aren't getting more in stock) so I have a feeling AMK has stopped making them now. My last hope is a guy I found today in AUSTRALIA online who has one and said he'll look into what shipping to the U.S. would be for that. I should probably post it in the Parts forum here too and see if anyone has one laying around their garage for sale.
C2AF-10505-B- original/correct regulator for OTHER 1962 Ford cars (T-Birds, Galaxies, trucks), ONLY came with Silver stamps, were NOT installed in early Mustangs BUT are considered "Concours correct" for judging purposes according to multiple Mustang sites. This is what threw me- Concours correct does not always equate to "original" parts, which finally got through to me today.
Would love to hear from any judges out there (Charles?) to see if I'm closer to the truth here than when I started...
Sorry this got so long!
Mark