[quote name='TPTroll' timestamp='1460136473' post='3023029']
Right, ok, turned my attention away from that one as it sounded too confusing.
But, then I found this bass with another neck issue. Neck bowed, but truss rod at max. Truss rod replacement, or just putting a new washer in at the nut?
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Looking carefully at the lower picture I get the impression of an 'S' shape going on here.
To me, there is almost a back bow at the first 2 or 3 frets nearest the nut, then there seems to be a fall away from approx. the 6th fret before starting back upwards at approx. the 12th-13th fret.
I'd leave that one well alone as I suspect you'd never find a suitable action on it.
Tightening the truss rod would amplify the 'S' and loosening would probably result in a fairly pronounced bow.
G.