bow in fretless neck

[Axtman]

I have a MIM Fender Jazz neck that someone poorly converted to fretless. (Not me! ) The board is rosewood and some joker RIPPED the frets out. The slots were filled with some sort of wood filler. It looks terrible. The neck has a bow that I can not relieve by tightening the truss rod. I have already tightened the truss rod quite a bit and am afraid about snapping it.

Any help would be appreciated.

[Marton]

Lower tension strings could probably help.

[Hookus]

And loosening the truss rod nut all the way, applying some lube to the threads, and starting from scratch, that way you know for sure how tight it is.

[joeyl]

the wood filler is the problem, it is too soft to replace the metal tang of the frets in the board. If the instrument is worth it (like sentimental value and such) I would remove the wood filler and place maple veneer instead.