What interior? Is it a Grande, Mach, standard interior car?
Black pinchweld was applied after the engine compartment black was applied which took place after the exterior color application.
Front fender not yet installed so there should be no black from the process on the fender and overspray fell on panels and details behind the pinch weld and in the rear wheel well as the spray stopped then restarted again behind the rear wheel well. Practice was pretty much standard between all the plants
Edge on the rocker panel was a soft edge (not produced by masking off with tape) and the edge can differ depending on the specific car but most like to produce that outside edge on the underside of the rocker so it can't be seen. That is of course if you don't have any documentation from the specific car before disassembly
If I knew when your car was assembled at Dearborn might be able to post a picture or two from that period