It’s interesting to see the dial variation on the copper dialed watch; on the top left sub-dial, it has markings in 20 increments rather than 15. I have seen other dials like this - perhaps it is a later variation as the later version of the 2447 with non-radium solid dauphine hands also has this configuration on the sub-dial

The copper dial version is a spectacular watch, thanks for posting Jeff and Abel.