I'm no Breitling expert, but the ref. 817 is known to me from an interest in military chronographs. It belongs to the "Cronometro da polso Nr. 1" or CP-1 spec, and was issued to Army Helicopter pilots, as the listing says, according to "Military Wristwatches, Sky Land Sea" by Galizia. In the two or three examples I have seen, movements are typically not signed. However, caseback markings are invariably present - it is not clear if they have been polished out on this one. It is smaller than the Bunds, the italian equivalents of which belong to the "Cronometro da polso Nr. 1" or CP-2 spec. The CP-2 are by Universal Geneve, Zenith and Leonidas. As far as I know, Breitling is the only CP-1, but I'll have to check Galizia again. For your amusement, here are my CP-2s - btw, screwbacks on both of them.

: Just when I thought that I had seen just about every shape and
: style of vintage chronograph, along comes a new one --

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: http://cgi.ebay.com/vintage-BREITLING-817-Italian-military-chronograph-/250815888987?pt=Wristwatches&hash=item3a65cabe5b

: said to have been made in small quantities, specifically for
: Italian air force helicopter pilots; powered by the Valjoux 236.

: so who is an expert in these? what more do we know about them?

: I suppose we can never say that we have seen them all.

: Jeff

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