Hi Doug,
So there's not much in the file, as this was only in index card form. But here's what I can tell you:
model name: Series I
model number: MSBI-4
top: Peruvian Walnut
accent: none
body: Mahogany
back: Peruvian Walnut
neck: 5-piece Maple and Purpleheart
scale: 32" medium
fingerboard: Ebony
inlays: mother of pearl ovals
originally made for: Rothschild
birthday: January 18, 1978
This is a case where the serial number was issued in 1977, but the bass wasn't finished until early in 1978, as the peghead stamping had to happen before the finish or it would crack.
Your bass already has an amazing story! I've updated it to have a file and included the details you shared above.