Rare RS-3 – Prototype?

[Xperiencer]

Hi everyone,
I'd like to share and get your insights on a very unusual Larrivée RS-3 that recently came into my hands. It looks like no standard RS-3 I've ever seen, and I wonder if anyone here has seen something similar before.
Specs:
•   Neck-through RS-3, mid-1980s (approx. 1984–86)
•   No serial number on the headstock
•   Fingerboard with keystone / wedge-shaped mother-of-pearl inlays (never seen these on an RS-3)
•   EMG active HSS system (2x Single, 1x Humbucker, active battery compartment)
•   Kahler Pro tremolo (PAT 4457201 DS)
•   Schaller W. Germany tuners
•   Condition: Great – no scratches, no wear

This combination of features – especially the inlays and the missing serial number – makes me think it could be a prototype, pre-production model, or a special custom order.

I've attached detailed photos of the inlays, EMG setup, Kahler trem, Schaller tuners, and the electronics cavity.
Has anyone here come across RS-3s with similar inlays or without a serial number?
Any insight from collectors or people who were around the Larrivée shop in the 80s would be amazing.

Thanks a lot in advance!

Michael