I think you are right. I do know that my 1965 Rambler had a PCV valve, but my parents’ 1960 Rambler had a road draft tube. I think 1963 was the year.
Well if it didn’t have a PCV it had a road tube,no way was the engine existing without some kind of crankcase vent,even if it was just open to the air.
I can’t figure if the OP seeks better mileage or reduced emmisions,he hasn’t stated he had the car sniffed and had poor CO or HC readings.
After the engine is in tune he can look to other areas for better mpg.