What was mounted on my FIREWALL?

[Veedubcollector]

Three holes across the top and two beneath. The holes are inset and almost appear to have accepted a tapered secrew head. Nothing looks as if it mounted inside and the car was obviously painted after the holes were filled with filler. Any helpful suggestions appreciated. And YES i would like to reinstall what ever it was to take it back to the correct time period. To answer a simple question in advance I would ask the original owner but he passed away years ago.