Rolex Chronograph (I dont think so)

[T5AUS]

but would apprecitate an opinion or three. The dial looks like it has Rolex on it, the inside back cover has a Rolex logo but there is nothing on the movement. I just dont see enough of this kind of thing but I would have thought it should have Rolex markings on the movement. What puzzles me is, if it's a fake, and a very old fake at that, why didn't the fakers put a name on the movement to make it more convincing. Did early Rolex chronos use none Rolex movements? There are no marks between the lugs.
Thanks guys