No clues at all. For sure speakers were at one time mounted in the package tray but two sets of speaker wires were in the car, a set on each side. Neither were connected to a pair of speakers because the speakers weren?t there anymore.
Regardless, nothing was attached to these holes. Didn?t really pay much attention, or notice them, until I removed the wheelhouse sound deadening.
Interestingly what I did see in the Osborne book was a reference to Falcon trailer towing wiring attachment points. The illustration looks to be exactly where my holes are. Maybe an assembly line worker thought he was working on a Falcon!!