[Healeys] Hole in Trunk Wall Question

[Mark and Kathy]

I am putting in the new trunk armacord and noticed that the old, 40 year old
"trunk wall" armacord had an extra small hole cut in it below the "main feed"
battery cable  hole.  The trunk metal wall also has a corresponding hole that
matches up.   What goes through this hole, or is it not used or maybe added by
a PO
for his  8-Track cables. :(

These holes would be hidden behind the "gas tank filler neck cardboard cover"
so are hard to see in most pictures.

The car is a 1960,  BT7.

Thanks,  Mark