So I've been working on an old Acoustic Black Widow, which obviously needs some work. After getting the dead pickup sorted, I am having issues with the set up. First off, I put on a fresh set of DR steels, and accidentally cut the A string too short (rookie move). So I had to use a Dean Markley (Solid Bass I think) nickel A string from my stash. After setting the intonation, re-checking, and setting again, something is still off. For instance, if I play/fret a 5th interval on both the A and D string, it's out of tune even though the open strings for both A and D are set to be in tune with intonation set @ the 12th fret. This bass has a zero fret. I noticed that the nut (metal) was sitting kind of low and the strings were definitely wearing down on the zero fret. Thinking this might be the issue, I shimmed the nut to sit a little higher, but that didn't seem to do anything. The neck relief looks in-spec for a bass this old, i.e. nothing glaringly wrong. I'm going to take it to a pro, but want to make sure I'm not missing something....???