Since there's no IWC subforum, this is probably as good a place as any to make a few inquiries. I've done a few searches, and seen some information and old catalogue pics from @Tony C. and @gatorcpa among other members, so maybe they can help with these questions:

1) When did the automatic calibers (8541 and similar, with the Pellaton winding system) start hacking?

2) When did the IWC logo first become applied metal instead of ink?

3) When was the Yacht Club bracelet (reference #10) first offered?

Thanks in advance.

 

1) I believe that most, though not all of the cal. 854B/8541B (first introduced in 1969) – the final step in the evolution of the cal. 85x family – hacked; some 854/8541 (from 1964) also hacked, but a far lower percentage

2) right around 1970; not sure if it would be possible to refine it any further

3) right around the same time; late '60s catalogues typically show the ref. 13 on Ingenieurs and Yacht Clubs, while later ones show the oyster style