Yes, they painted them assembled, my point was they also painted the rubber bypass hose and hose clamps. So to me, any "fancy forethought" of what the effects of paint had on parts and sealing, likely were only those of convenience and assembly speed.
With an iron pump, painting it all was easier on the assembly line. In fact, if I have an all iron one, I paint it assembled too, why paint a bare block when you need to paint the pump and bolts too? However, if an alum pump, I paint the block and do not scrape it. If we want to get real geeky, what happens to the hoses and edges of the gaskets when paint leaches under them? Again not an issue in the real world, but neither is paint or no paint.
My larger point is that we are arguing about something we have never tested formally. Some of us think the paint will fail, some think it won't, neither have had an issue. That's the punch line, the water pump...machined surfaces on both sides...likely has the easiest pair of surfaces to seal on the entire FE, other than being careful on the one bolt threaded into the water jacket. You can go paint or no paint, sealer or no sealer, cheap or expensive gasket, I never see ANY leak. So no testing, no failures, seems like a lot for nothing.