Your heater control panel and woodgrain center panel is exactly like the ones in my documented '67 non-a/c coupe.

Mine also says "air" which I believe opens up the vents to let air in without assistance from the blower fan.

However, my firewall does NOT have the 2 holes with rubber grommets your photos show ABOVE the heater core cover on the engine side.

My car WAS originally built for sale in California. The A.I.R bracket for the passenger side is similar to the support bracket for the power steering, but both are "hollowed" out so that they create a passage to the small freeze plug openings on the front of each OEM cylinder head to allow air to be "injected" just prior to the exhaust gasses exiting the cylinder heads. So the A.I.R pump bracket is more horizontal than the vertical one that your photos show.

I believe I will go with the opinion that your car had dealer installed A/C