There are a lot of Ithaca SBTs out there with chipped finishes. My inclination is to live with the chips unless they really get under your skin. The other issue those built-up finishes have is cracks, but that's another story, another day.
I would stay away from any thinner. That stuff can run amuck.
What I would do, and I have done this before, is build up the chipped area with dabbed on lacquer, thin coats at a time, and then take it down level with the original finish with something like 1000 grit paper, and finish with a polishing compound. Agonizingly tedious.
