What goes through these holes in the firewall?

Maybe dealer or aftermarket a/c who knows? There are no obvious signs of it The heater controls are standard there are no extra holes under the dash , no odd ball vents or other hoses. But it is a 53 year old car that isn't completely stock or unmodified. When I bought it there were wires through the double hole with a big gob of black dumb dumb sealing it.