Well, first of all the gen is split-second chrono, while the rep is just chrono (as far as I know, no split-second function has ever been repped, on any watch).
A second flaw is in the chrono and reset pushers. They should be of a same shape, the shape of the reset pusher, while in the rep they are different, 163-like (btw, the 163 is simple chrono).
I already modded this, but had no time to take and post pics of the modded result yet.
A third flaw is in the subdial at 6 o'clock.
The good news is that, having the 147 been made in as low as 35 pieces, very few people can spot it.
Here are side-by-side pics for your convenience:
Apologies to FxrAndy for this small hijacking -- you asked about 42mm PAMs