They've confirmed that a) the 42mm Eureka hand won't fit if anyone was thinking of trying to retrofit it and b) there are no plans to put one on the 38mm as the 42mm was the original watch in the film.
Understandable, but a potential massive marketing screw up. I'm certain they'd sell by the bucket load if they changed their position on that. After all, size didn't change the appeal or success of the Speedie.