I agree everything looks legit other than the board. If the owner has had it since 1984, then the work must have been done early on, and IMHO makes it more likely that it still has the Ric truss rods. OP, do you see the original rods under the TR cover?
My one question is, how thick is the fretboard? Ric boards are very thick, so if this has a 3/8" thick board or so, it's one more feather in the cap of being a real ric with a replaced board.
My one question is, how thick is the fretboard? Ric boards are very thick, so if this has a 3/8" thick board or so, it's one more feather in the cap of being a real ric with a replaced board.