If you surf throught the WALBERNIZE
website, you will see that they do NOT recommend cleaner polish and glaze for clear coat finishes,
but they say the RV superseal is safe for all finishes.
You might want to call them on their toll free number or email your question. Note that their price is a bit lower than the Airstream shop.
It would be interesting to know what changed after 1974, other than the satin finish in 1982.
I wonder if maybe Airstream meant to say 1964
, since clearcoat was introduced as an option in the 1963