Looks like I've been given poor info. It's for a friend who is interested in the Bass. The person selling the thing said it was a 74 and gave a ser# as 00412. Mabye it it was B000412.
As an after thought, there are some prototype Pre-EB Basses around. They're prefixed with an "X" and five digits. They could date to 1975 but I doubt 1974. A proto Bass would look like "X00xxx".
So, "X00412" is a possibility, especially if your friend is saying 1974!
wow if it is a prototype that could be worth some coin. Poor guy, I'm going to get him all excited. hehehe I bet it turns out to be just a case of a wrong ser# being passed over the phone or something.