Rolex 116600 (or transitional model) question ...

[Dusko.Popov]

This isn’t a question about the future value of the sd4k. What I want to know if here has ever been a transitional model as appreciably different than the model that preceded and followed it?

Vis a vis the 16600, the 116600 gained a glidelock clasp with diver’s extension, engraved rehaut, crown-lasered anti-counterfeiting insignia, fully graduated bezel and a ceramic bezel.

Vis a vis the 1226600, the 116600 retained the previous 40mm case, the raised crystal, no date magnifier, and monochromatic writing, and existing movement.

This model seems like it differs considerably from the model that preceded it and the model that followed it. Just wondering from the Rolex historians who know references better than me, has there ever been a more transitional, transitional model?