My impression from the original post was the micro mini was resin (or pewter)... if I saw an ad stating a MM resin was "not painted", I would consider it unpainted, with NO paint or primer, especially if the seller states there may be some seams to deal with... although the paint can be stripped, it is extra work to do that... and if not stripped, some primers react with certain other paint or sealers...

The seller should have stated there was paint on it in the ad.