I don't believe a dingus ever existed in the position it now occupies, either. Or are we suggesting that this isn't a retcon and that the dingus was on the physical model? (Myself, I've always been comfortable, and rather charmed with the idea of no visible emitter for the phasers. And by "always" I probably mean "since 1992".)
Unfortunately I'm not keeping track of the many threads on many boards, but someone somewhere did produce a photo showing that it WAS on the model.