I agree; they were all installed by the original purchaser, but as an option. In Oklahoma, you would be a fool to buy a car without a heater, but they did...(very rarely)...show up from time to time, and the occasional older car with the gas heater. I suppose some of the old tightwad farmers bought the occasional truck or car without a heater, but it still makes no sense. Radio was different; I don't think I ever saw a radio in a 30's vintage car (original) and most of the early 40's that I recall didn't have a radio. I had a 30 Chevy, a '41 Chrysler and a '41 Chevy and don't recall a radio in any of them. Both my '50 Chevys had radios, and everything since.
I believe that radios were not available in '30's vintage cars until quite late, and they were very expensive.
If you lived and grew up in rural Oklahoma in the 1950's, your car had to have a radio, especially if you ever expected to have a date! If you went out parking, you parked on a hill so when your ran the battery down, you could put it in gear, push in the clutch, and push it down the hill and start it that way. You either double dated, or your date had to know how to push-start a standard shift! Ah, those were the days.
My Dad told me that on the '20's vintage and earlier cars, bumpers, self starters and I think Windshield wipers were all options.
