Steve-
There's no local license service that has any clue about this. Furthermore, there's not likely anybody at your local Secretary of State's office that knows about this either. You'll need to act as your own agent.
You'll need to print out the link I gave you, follow the instructions to a "t", then send the entire packet to the address provided in the link. This is a different process than when I did it in 2005, and it's a lot easier (I had to schedule an inspection by a specific street rod club).
Once you've jumped through the hoops, you'll be eligible for antique plates ($5 a year, or something ridiculously cheap), etc. then the only hurdle you'll need to jump is insurance, and that's a whole 'nuther kettle of fish.
Forewarned is forearmed.