IWC Cal 61sc 35mm 1938

Hi all, i'm embarrassed to say i'm an infrequent flyer here. So hi all. I've a few IWC's....well 2 MK 11's and an Electronic, and now i've another. i'm looking to learn more about this obscure calibre. I do know that roughly 8K of watches had this calibre, though the range of watces accommodating the Cal 61 i know not.

Here's my 35mm 'pilot watch' type centre second (missing pinion and sweep hand). I've only seen another of this type, which had a cream dial, otherwise dial hour/minute numbers and railway tracks the same. Seems pretty big, relatively speaking for the calibre.

I'm tempted to get an Archive extract on this one, as it appears to be a potentially interesting and rare watch, does IWC still do? Does any one on here recall seeing similar?

All the best

Paul
[](imgur.com/Vvu9kyM)
[](imgur.com/5mgqmuZ)
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[](imgur.com/mCwH3sJ)

Hi Paul,
I remember you from the military forum in the UK as an expert on military watches. Welcome to the Forum.
What I know about IWC cal. 61 is the folowing. It was the forerunner of cal. 89 in your Mk 11. A small calibre with centre second, hand wound. Due to its size often a ring was used to mount it in a larger case as needed for its 10 ligne format. It showed up for the first time in 1938 and production ceased in 1942. Nearly similar movements were calibre 60 and 62. It has been used in ladies wrist watches and with a larger case for men. As far as I know it was never considered as a pilot watch, nor for civil nor military aviation.
I do not see the need for an authenticity extract of the archives. The watch looks genuine to me as well as the case with ring. An extract would cost over 300 £. I do not recognise the dial but there were many variations around.
Kind regards,
Adrian,
(alwaysiwc).

Dear Paul,
I second Adrian:
(i) The Cal. 61 is the forerunner of the Cal. 89. Not very often seen, but as well not really sought after by collectors (for what reason so ever).
(ii) Definitely no mil. background, so not really what you are focused on.
(iii) The Certificate of Authenticity might be too extensive for this watch. I'm afraid you won't get that money back, when selling the watch.

Greetings to the UK

Thomas Koenig

I had at one time three of these IWC Ref 304, anti-magmet, hermet wrist watches with cal 83 and cal 61. All had been sold to Sweden in the 1940s.

Thanks a lot gentlemen, some interesting info. Wow the extracts are expensive! So thanks for the heads up. I'm glad that the watch caliber has been overlooked in a way. my experience of this is that it's best to get in before the crowd. Having a 1938 35mm stainless steel fixed lugged black sterile dial iwc with antimag shielding with SC for £500 seems a good investment. Add rare calibre and has all the ingredients for a future classic.

Thanks again for information.

£500 for one of these Ref 304 to Ref 309 is an excellent find and even a good short term investment. These IWC are highly appreciated by Japanese vintage collectors, who appreciate their small size.

here it is next to the MK 11. Diameters similar, but much shorter lugs.
[](imgur.com/Yr2Ef6G)