Starting to have a bit of buyers remorse....................truss rod stuck in either direction. E and G string not as loud as A and D, pickups don't cover the span of the strings. The string trees don't hold the strings down they keep popping off. Upon taking it apart it looks to have been built by a 8th grader with a coping saw. Sigh............................... I expected better.
Ah, yes. Sounds like a Waterstone!!
Now you know why Petersson has all the hardware and electronics replaced, despite "endorsing" the brand and getting paid. Hamer never paid him for all the years he bought his custom-made ones they did....which pretty much laid the groundwork on root-octave basses. Even some of those early single-truss ones eventually went bad after being beat to crap on the road...but all the dual-truss ones are still alive.
Shame about the truss rod on the Waterstone but single truss rods on import 8/10/12 string basses is a crap shoot. Have you tried loosening up all the strings, pressing down on the middle of the neck with it across your legs to relieve any tension and then tweaking the truss nut? That will usually get you a bit more life out of it, if its really tightened down and the neck is still bowed.