I don't believe the story that the Mesa V30s are the OG formula after Celestion changed the others. I think whoever told Fryette that was misinformed.
I have some T3904 speakers from '89 and some early '93 T4416 speakers. They are visually different. The 3904s have a larger, cast back plate (silver metal part behind the magnet). The 4416s have a smaller, machined back plate. I assume the Mesa spec was just a different OEM order from the beginning.
They also sound different. The '89 T3904s are brighter and a bit scooped, turning any amp into a bit of a chug monster. The '93 T4416s have a smoother/more syrupy top end and seem more balanced.
In the early '90s, Celestion changed the doping around the dust cap, but that seems to have happened to all the V30 versions, not just the 3903/04.