(...)

The models don't need stripping anway, really - it was entirely my own fault for using metallics, which simply don't look right on the small base ships and are probably too thick to use effectively.

I find a thinned down base of GW's foundation paints (or whatever the current equivalent is) is enough to provide coverage on an existing paint job without obscuring detail, then a thinned down colour, wash and detailing.

Yes most you can painted over like they are. However the HWKs have some brown polymer as base, so i stripped 2 of those, as i had problems painting one of them blue.