Thanks! This is not so that's why I bought something I fell in love with. I'll sell the one I have, the next owner will decide if it's a problem or not.A: grats on your bass, it's a beauty
B: the proper way to fix those issues are depending how bad the curve is:
1: level/recrown the frets
2: refret then 1
3: replain the neck(fingerboard) to straight then 2 then 1
alternative: change the neck and set up from there
Unfortunately most of the times it just does not worth the effort unless you got some really expensive or exotic instrument or You just really want to save it, cause why not.