After a year or so I finally got it made. The cover is made from 4 P-bass covers and the pickup is in a reversed position (ala Yamaha BB2000, Spector NS-2 etc.). Allparts Teleneck and some old Schaller tuners. The bridge PU will be replaced by a humbucker and I'll add a switch for mono/stereo.
A string guide will be added, it just don't look right without it.