The road draft tube / PCV Valve thing brings back a lot of memories. In the mid 1960's, one of the first "emission" laws the state of California passed mandated PCV Valves. At that time, we wanted nothing to do with them. As far as we were concerned, they were:
A) A giant Vacuum leak
A source of oil contaminated air being sucked back into the engine.
The general consensus was “Who wants to suck that dirty oil back into the engine?”
Back then, guys who bought cars that had PCV Valves took them off and installed road draft tubes and vented oil caps. What we didn't know at the time was the closed crankcase system would extend the life of an engine over the Road draft tube system because dirty, “road draft” air was not being sucked in to the engine during deceleration to contaminate the oil. What we ddin't know was PCV valves did way more good than harm.
Since the Shelby's were produced in California, it was always assumed that they all had PCV valves. I talked to a guy who has a 65 GT-350 that is earlier than mine. It was originally sold in Arizona and has a road draft tube on the right valve cover. I asked him about this, he says it's factory and there is another 65 originally sold in Arizona that has the same setup.
Live and learn.