I am still here, lurking in the wings...just hoping Mica might be able to check for any info on this FINE Bass. I am still playing and loving it. I wanted to put together a page for it, but I have been waiting for any info. Thank You Mica, hope all is well with you and your family.
Link to pics: http://club.alembicguitars.net/Images/395/116778.html?1325200131

Here's the details I found on your bass:
 
serial number: 76-508
model name: Series I
model number: MSBI4
top: Bird's-eye Maple
accent: none
body: not recorded, but it appears to be Mahogany
neck: 5-piece Maple and Walnut
scale: 32 medium
fingerboard: Ebony
inlays: Abalone
peghead veneers: Walnut
pickups: SC-1
controls: Series I volume x2, filter x2, Q-switch x2, pickup selector switch, stereo 1/4 output, stereo 5-pin output
originally made for: Rothschild
birthday: October 4, 1976