I've just purchased a cigar box guitar from a very experienced maker who uses a fender strat scale to position the frets. The octave position is spot on, but if I depress a string near the nut they are out of tune. the first fret or two are out by as much as 20 Cents. It gets better as you go up the neck. The action is 2mm at the first fret which is fine, cant get it much lower. So how can I overcome this problem? Seems to me a strat has a lower action and probably shallower frets. How can I adjust the scale (on the next guitar I get) so it's better in tune?