sidanyilmaz99
4
Possible Original IWC Ocean 2000 BUND Transitional Case Back (3501 / 3509)
Hello everyone,
I would really appreciate some opinions from serious Ocean 2000 / BUND collectors regarding a very unusual case back configuration that I recently inherited.
What I currently have is an original IWC Ocean 2000 BUND case back with:
Outer military supply number:
6645-12-197-9681
Inner reference stamping:
3501
As most of you probably know, the supply number 6645-12-197-9681 is usually associated with the later Ocean 2000 BUND Ref. 3509, while the inner “3501” stamping would normally belong to the earlier reference.
After a lot of research, I found several discussions suggesting that during the transition period from Ref. 3501 to Ref. 3509, IWC apparently reused earlier 3501 case backs for later 3509 military production. Some collectors mentioned that the inner reference numbers were sometimes changed from 3501 to 3509 — and sometimes not.
This would potentially explain why this case back has:
- the later 3509 military supply number on the outside,
- but still retains the earlier “3501” marking inside.
What makes this even more interesting to me is the provenance:
I received these parts directly from a watchmaker who worked on watches for the German military / Bundeswehr, so this did not come from random parts trading or aftermarket sourcing.
From what I understand, this supply-number configuration would also originally correspond to:
- a flat mechanical 3H military dial,
- orange minute hand,
- and the mechanical caliber 3752.
So my questions to the community are:
- Has anyone here ever seen this exact configuration before?
- Do you believe this transitional setup could genuinely have left IWC this way?
- Could this actually be a rare and historically interesting transitional military case back?
- Has anyone ever encountered a 3509 military case back still stamped “3501” internally?
- And finally: does anyone happen to have the correct mechanical movement (Cal. 3752) or possibly additional matching parts for this configuration?
I am currently also in contact with IWC Heritage to see whether anything can be confirmed through their archives.
Any opinions, experiences, photos, or archive information would be hugely appreciated.
Thanks a lot!
