Spoke with a friend in CO who owns '65, '66, 67, '68, and '69 Superiors (among others). He confirms that Superior did not change (from waist to roof) and in fact
most glass interchanges '65 through '70 (although he's never owned a '70).
Vent window changed in either '69 or '70, so front door glass is also different from then on.
Sovereign-to-Sovereign and Royale-to-Royale rear loading door glass, as Micheal pointed out, is the same. In fact, he's positive that the rear loading door stayed the same as well from '65-'70 (again, allowing for distinction between Royale and Sovereign glass sizes).
He also pointed out (not that it applies in this application) how easy it is converting a non-Crown to a Crown, as C pillars are already canted between models. The fact that Superior's roofs didn't change for a multi-year run is more than acceptable given how Superiors
"blew other '60s coach designs away" to him.
^Isn't that always the case though, regardless of year?