Custom Deluxe and higher window trim on a plain old Custom (72)

[jocko]

Quick question for a 72 expert... Custom/10 came with no window trim front or back. Classic Industries sells it pretty cheap. But also gives the warning "for use on all vehicles that accept window moldings". Does anyone know if the trucks that originally had no trim can easily have it added or do special clips need to be added to the window channel. Never owned one without the trim, so not sure if you can't just "slap it on there". Thanks.