Good afternoon to everyone.
I hope you can help me with specs of my Alembic Elan with serial number 90H5771.
Thank you very much)

Looks like the regular woord recipe for an Elan (maple and purpleheart 7-piece neck, maple core). Guessing it's a tulipwood top, and it looks like someone at some point attached some sort of medallion. Elan Plus electronics (bass and treble boost and cut switches).

Adriaan has the basics down! Here's the list of things from the file:

top: Tulipwood
accent: none
body: Maple
neck: Maple and Purpleheart
scale: 34" long
fingerboard: Ebony
inlays: Pearloid (plastic) ovals
pickups: AXY56
controls: "Elan+" volume, pan, filter, Q-switch, bass cut/flat/boost, treble cut/flat/boost, mono output
originally made for: Mesa Boogie, Germany
birthday: January 26, 1990

The bass was originally ordered and routed for standard Elan electronics, but there's a note that it had "Elan+ electronics installed in a regular Elan cavity - control pattern is NOT standard" and I was thinking the switches looked a little cramped. Last minute change before we shipped it to Germany I guess!