Not 100% of the time, but most of the time....Cadillac ambulances received etched glass, Cadillac combinations received plexiglass window inserts.
Have seen Pontiac(s) that used plexiglass ambulance window inserts.
it would indeed depend on year and modal what was used. the first set looks to be MM but what is the second set of from. I'm guessing amble wagon. these type of inserts were used on ambulance also not just combination cars.
Hey Bill, post a pic of them after installation. I know I'd really like to see them.