"HELP" advice, opinion on reconditioning maple neck and fingerboard.

I have been extremely fortunate to acquire my first Musicman Stingray ‘CHEEP’ although it is in desperate need of a good clean up with blinker fluid and oil change.

First and foremost I have identified that it is indeed an authentic EBMM Stingray 4 with 3band EQ, and a 10-4-93 all maple neck and Sept-2-93 black body. Serial# 38669.

Cosmetically, mechanically, and paint wise the body is in relatively good condition but its the finish on the neck that I have concerns about. The neck and fretboard appear to both be maple with a figuring of birds-eye that, in itself is in good order, but the finish seams to be stained with funk that just wont clean of.
It can be seen in the attached pictures that there seems to be discoloration on the fret face between the strings and on the back of the neck.
I have cleaned the fret face with OOOO steel wool and paraffin oil and then rubbed with isopropyl alcohol but it seems to have had little to no impact.

So this poses a couple of questions:
1. Is the neck and fretboard finished with a hard laquer or similar?
2. Is this the color and look they are supposed to be? (just looks dirty to me).
3. Is it advisable/possible to sand the surfaces clean and just oil with something natural?

Thanks in advance to the brains trust and anyone who has taken the time to read.

Greg.