I've had this bass for about a year, bought it at the pawn shop. It looked like new when I got it. It's my first electric one. It's a fret-less warwick streamer lx jazzman with a bolt-on neck, the neck is made of Ovangkol and the fingerboard of Wenge. The neck has an upward bow (the direction the strings are pulling) and is impossible to fully counter with adjusting the truss rod. I've turned it as hard as I dear to, and in the end the neck always starts to make bad sounds. So now I have removed the neck from the body to have a closer look, measuring it against a table (don't have any tools) just to see more closely how it looks. I shows that it has a slight up bow even when the rod is tensed and the strings are of, and way to much up bow when left without string and rod tension, when it actually should be straight. So it's never straight, and far from back-bowing. It's not really a big problem for me, I actually prefer to have little extra up bow since I like to play the strings with a lot of power. But now I need to sell it and thought I'd check if anyone now if there is anything I can do to straighten the neck out.