I think I now know.
For a 1965 car, the CA DMV does not require a SMOG test (certificate) to changed the title (i.e., sell the car to another person)
If the car is "non-op" then it is retained in the DMV system, so does not need to be "DMV/CHP/Private" VIN and vehicle verified.
If it is NOT on a non-op status, then it needs to are "verified" ... in which case, any vehicle 1968 and newer has to have the Federal Safety stickers, and as mentioned elsewhere, ALL the SMOG equipment as originally delivered and sold in California.
I found that by 1966, there were some additional "emissions" item of those cars, and I do not know that, if a car needed to be DMV/CHP?Private verified because is is NOT in the DMV system (i.e., was not on non-op status), that it needs that emission items. I suspect just vacuum hoses to keep from dumping fuel into the carb on throttle off, etc.
Once registered, any 1975 or OLDR car does not need the biannual SMOPG check, but if the car is inspected, say by a CHP on the side of the road, speeding ticket, they can inspect the car for the SMOG equipemnt, and if not there, flag the car to a BAR referee ... who do KNOW what parts were on gather car. They (BAR) have a national database for the parts, so there is NO LIMIT to the code to being the car into compliance. If the parts do NOT exist, you are only given a 2 year exemption. After that, the car cannot be used on the road.
A private verifier I spoke with filled me in on the process ... . The first question he asked, "what year" ... as if 1968, I can't do it without the car having all the federal safety stickers, etc.
Hence, a 1965 Mustang is "golden" ... needs nothing.
This is now my understanding, having gone through the system.
What one wants to avoid, is getting "kicked" the the BAR referee !!