Any chance this item may be due to dual exhaust? In 1970, there were variants of fuel line wires due to the presence of single or dual exhaust.
Chance? Yes but maybe not all dual exhaust cars sine we have allot of dual exhaust examples with the typical rubber coated clips. Though that style may have been used for that application for a specific period of time. Have to remember that using the sleeve style required additional effort and work for one or more workers
Hopefully the survey will help narrow down the possibilities as it already has done eliminating it as a Cougar only or workers commonly installing the wrong one on the wrong car model
As for the holes I asked about above. Have come to the conclusion that no the holes in the passenger side lip are not a prestamped feature so I can used those to count those cars with them in the long plastic strip/sleeve category in my searches