x3 I paint the components & then assemble, like Ford did the Model A.
With a Model A you'll lose show points if the head gasket edge is painted over, etc.
But at some point Ford went to painting the whole engine AFTER assembly.
Could be when they went to Ford Corporate Blue - so all the gasket edges, bolts, engine lift hooks, etc, all Ford Blue, valve covers already on.
Not sure when things changed over - eg how were the flathead Fords done in what years?