do you have serie schematic please?
sorry for my english!
thanks

I can mail you a schematic. Email me your address for receiving a letter and I'll send you the schematic.  
 
Please do look under the pickups for a handwritten number. This may be able to identify the bass. The `6`2 is not something that I recognize. Also look at the pots - see if there is a 4 digit number written on one of them.

the number under the pickup is#394

We'll start researching and see if we can find a cross reference for this number. Thanks!

thanks ,Mica,for the schematic !!!!!!!!!!!

I Mica,
A question about the neck pickups.
I think it be rectified,the magnet have less punch than the bridge.
it is normal???

The pickups should be identical. You can measure the restistance and see if they are a close match. Usually the neck pickup is farther away from the strings. You might want to increase the gain with the trimpot on the back.  
 
Today Bill found the work order for 394, but it did not match the pictures of your bass. It was for 83-2769, an Exploiter Series II with no humx in Quilted Maple. We'll keep looking for clues!