A friend of mine has an old and cheap acoustic dreadnought from the early 90's ( Hohner HG-3000 Made in Indonesia, laminated mahogany). Everything was off, strings unchanged from the first day as far as I can tell. I am trying to make it playable again (or maybe for the first time). Among other minor repairs I did the following: Filed the nut slots deeper. Adjusted the trussrod, neck is straight. Leveled the frets to take care of wear and high frets. Replaced the straight plastic bridge saddle with a new compensated graphtech saddle and lowered the action to 2.5mm (12TH fret). It was strung with really big strings like 13 or 14s'... Hard to say with the rust... The idea was to lower the action and use a lighter gauge of strings if possible. So I replaced the strings with a set of 13-54. The action is low and it plays smoothly. My problem now is that the intonation is off, the note played at the 12th fret is flat by nearly 10cent . The beginning of the neck is OK but you can hear it when playing from the 8 or 10th fret and it goes worth . How can I correct this? I think about raising the action a little, or trying a higher string gauge like 14-59 (those are not stocked by guitar dealers in Paris, I would have to order) or 16-56. Maybe need a different tuning then. Would this be enough? I don't want to sacrifice playablility either. Any advice is welcome.