I’m so impatient sometimes...
My gut said “prime it”, so I ran down to Hobby Lobby and picked up a can of Tamiya fine primer, first time I’ve used it... boy is it great stuff!
There’s only light green and black on the cupola, and no lettering, so once the green cures I can mask it off and hit the roof with black, then flat clear the whole thing and the cupola will be done...