I am only sharing what I saw in the shop. I worked ‘66-‘80 in Ford dealer as tech and began in ‘66 as accessory installer and pre-delivery,etc. It was common to remove sill trim to access or add wiring through the area in rocker for many reasons. That gaffers tape was very common to hold wiring down into the recessed area and at edge of carpet. Not done very neatly most times as it was only there to hold in proper location/out of assembly line workers. Once the wiring was in proper location it was much safer for workers to install sill trim. As a youngster back then I was quickly educated by older,more experienced techs that wiring,either factory or added must be protected. Any incorrectly installed screw can,and did,wreak havoc down the road. That same tape was applied over many exposed sharp edges that wire looms were routed through. When in doubt,apply enough tape to secure wiring safely during assembly. Judges don’t see it,and was never meant to be seen. The assembly line was a messy affair at times with excess glue,caulking,extra parts,leaks,etc. The pictures that Ford released of milestone cars on the line were not even close to average conditions. Blood,sweat,tears........