i am not positive but i think Automatic was taken over by Yale in the early to mid 60's so it's going to be tough to get a number. i hope you're not considering buying that thing for $10,000. i can get you one less than 6 years old with a certified battery and ship it to you for that much and i am not in the sales bsns.
look around before you buy you can do better. (unless you are looking for a nostalgic restoration)
it looks like it has frame ground. WOW