Looking at the pictures, engravings are perfectly legit to me,
also case has one single triangle behind the lug that means the watch was born with cal. 11.
Bezel was matter of choice, we saw many pics of Jo Siffert with an MH bezel on his own watch.
Only matter of discussion in my opinion are dial and hands:
dial seems a bit early - i saw mostly the mk6 dial with 1-12 counter from the 204xxx serials -
while the handset seems a service one because of its very light blue.
I have to say that not all Siffert dial executions have the index in the same blue, so this is possibly another
cause for this mismatch.

Paolo