Not sure what the problem is here, isn't a neck supposed to have a back bow when it's not under string tension?
I would put some strings on and see if it needs truss rod adjustment.
A 4001v63 has the modern 4003 truss rods, easy to adjust.
FWIW, I've had some first-hand experience with a not uncommon RIC truss rod problem: The rod ends dig into the wood on both the body and nut end, this makes adjustments difficult or impossible (no threads left to do the job).
The problem at the nut end:
And at body end:
If this is the case here, I'll will gladly guide you in the right direction.
In the mean time, string her up and see what happens!