[MiraclePieCo]

Okay, here is the definitive answer (or at least ONE answer) to my own question, can you use late AD push button style doors (52-54) on an early cab originally equipped with turn down handles (47-51)? Answer: NO.

Not without modification, that is. The respective latches and strikers are not compatible. I didn't want to hack up the door jambs on my pristine cab, so I chose to modify the strikers instead - after all, they're easily replaceable. I ended up with hybrid striker using the center section from a late cab joined to the mounting tabs of an early cab. Seems to work great - door closes and latches fully.

Pic 1: Early striker, late striker, hybrid striker tacked together for trial fit
Pic 2: Late striker, hybrid striker for comparison. Note the difference in depth.
Pic 2: Finished hybrid striker ready for installation