I don't have a parts box... I have a dozen or so parts BOXES, lol... Plus parts-bins, parts-drawers, and parts-crates... I've been building and tearing down models for 40 years, and have parts and more parts, and parts of parts... (I don't keep many models, preferring to build, photograph, and tear down)... But I reckon that if I had to, I could resurect about 100 models from the parts on-hand... I've always wanted to organize them, but it just ain't gonna happen.. It'd take weeks, if not months, and I just ain't that dedicated, lol..
The only real organization I do is for figures, by scale and nationality, and their weapons, and battle-rattle... Also Heads, torsos, right arms, left arms, right legs, left legs, etc... I hate stock figures, and I re-pose or totally reconstruct them into what I want, or need rather than what the factory thinks I should have.. Sometimes it's as simple as a turned head or raised arm, others are pretty elaborate...