I have a vague memory that there were about a half dozen of these basses modded back on Brady Street. Certainly not more than that. I've seen 2 others in person.
BUT, this was not done on Brady Street. The date codes on the volume pots are from 1975, which puts us in the Sebastopol/Cotati years. One of the filter pots was replaced with a 1995 date code pot from an Activator (which works fine BTW). The other filter pot looks like an original Alan Bradley type.
The wiring around the 5-pin reveals that my dad didn't do the work, but that doesn't mean that someone here at Alembic didn't do it. There are no records of repairs and modifications, so all I can tell you for sure is that the guts are Series I Alembic issue with at least one replaced pot. The silver shielding suggests that either we or someone that worked with us at one time did the work. I'm sorta leaning toward Alembic guts that Stars guitars installed. But that's just an educated guess.