That is interesting. I'm sure someone at DMV figured out that there's some tax revenue to be made, since original black plates often sell for a minimum of $200 unrestored. They'll probably charge an annual fee like their personalized plate program. But if they reissue the original "AAA 123" format, they might start taking the original plate numbers that are currently "Not On File," which means you won't be able to re-register an original plate with the same number in the future.
In reality, you can re-register black plates to your classic, regardless if they originally belonged to the car or not. Most DMV clerks are not familiar with the process, which is why so many of them would rather shoo you out the door by telling you it's not possible. All that's required is that the plates are not on file (meaning not currently or formerly registered to any car in their database), that they're metal (they're supposed to test them with a magnet if they can find one), and that they're legible enough to be displayed on a car. The process requires you to fill out a form describing that you want to re-register these plates to your classic car, the clerk's signature that the plates were inspected and suitable, and the paperwork to get sent off to Sacramento for a 4-6 month processing turnaround.
I was fortunate enough to get the original plates with my car when I bought it, though the PO had re-registered it to some newer white plates some time in the 90's. It helped that he also gave me some original registration cards from the 70's and 80's showing that the black plates were registered to the car at some point. The clerk at the DMV was incredibly rude and quick to turn me away, but I had done my research and argued for about 45 minutes to her and a supervisor before they did what they were supposed to do. They even tried seizing my plates, saying they needed to be sent back to Sacramento. whatever you do, DO NOT let them take them!! You'll never see them again! :nono:
I got my registration back in about 4 months, which is not bad considering our DMV. That was about how long it took to get the plates back from being restored.
A few other interesting things I learned- you are NOT required to display a current registration sticker on the plate itself, though it might be difficult convincing a cop that... or especially parking enforcement or a tow yard who impounded your car for not displaying current tags. I bought an original "1966" registration sticker off ebay and put that on, though most people do display the current sticker on a metal tab mounted near the plate to avoid getting hassled by cops or meter maids.
You're also not required to display a "month" sticker. Most people buy an old red one to put on (I did too), but in reality those were not original. California didn't start issuing month stickers until the early 70's, at which time they instructed people to put the month sticker in the left box and the current and future year stickers in the right, which is how they're displayed today. Most people who didn't have a month sticker prior to the new program simply put them on when DMV started issuing them, which is why many think the red sticker was original. In reality, before the switch in month and year sticker rules, the annual registration sticker was to be displayed in either the left or right box on the plate depending on the year- 65 was displayed on the left, 66 on the right, 67 on the left, 68 on the right, and so on, until the change.
I thought that was some cool history when I learned about it. The program now doesn't have the current requirements because the plates and car are considered "classic" or historic. So you can have an original black plate on a 65 displaying only a 1965 year sticker in the left box, or only a 1966 sticker in the right box on a 66... if you so choose to be "completely" California original.