I have never seen original examples where the splined stubs for the wipers and the associated mounting screws for those had stripe color on them so I agree it was mounted after the cowl was painted. The long horizontal part of the linkage is the one that occasionally has some stripe color paint on it where you can see it through the cowl vent. Whether that is due to "internal repair" or some other reason, I don't know. For guys who have their car judged, I don't want that little splash of stripe color to be considered wrong because it did legitimately happen on occasion.
Jon, I am in 100% agreement with your statement.