IWC 853-724, Balance staff

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  New IWC original balance staff, not in factory packaging.

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  Fits cal: 853, 8531

Versions: 13''' (1958 - 1963).

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  853: center second.
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  8531: center second, date, H=6,40 mm.

Versions: 12,5''' (1963 - 1974).

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  854: 21-25 jewels, center second, H=4,85 mm.
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  854B: 23-25 jewels, stop mechanism, H=4,85 mm.
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  8541: 21-25 jewels, date, stop mechanism, H=5,90 mm.
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  8541B: 23-25 jewels, date, stop mechanism, H=5,90 mm.