I'm looking for a lacquer compatible clear coat, that isn't lacquer clear. I had a guy paint some motorcycle tins, that he sprayed with old Martin Senour black lacquer (the real stuff from the 70's/80's) and some brand of 2k clear, he has since passed away. Over 10 years ago, paint and clear still look great. I know you can't immediately try to 2k clear over fresh lacquer, unlike base coat clear. Extend lacquer base dry time to let it fully gas off, then clear?
I'd bet most any 2K clear would work. I've used Kirker on tractors over lacquer and industrial enamels, well cured. But be aware that it won't crosslink as it does with base coat. So the lacquer will need to be prepped with the appropriate grit sanding, or maybe 3m Scuff-it. That will provide some tooth for it to grip.
It will be a lacquer base with heavy metal flake added, can probably get away with a grey scotch-brite. Planning on test spay outs, before applying.