Hermann, I believe the case for your watch is not from Heuer and not made for a Valjoux 7765 movement. As you can see there is a gap between the dial and the tachymeter scale which indicates the case is made for a Valjoux 7750 movement, which is thicker on the dial side than the V7765. Also the "13/1" marking is not correct, it should be "13 1". There have been several watches with incorrect cases and markings for sale both in Chronotrader and ebay. The watches did not leave Heuer like this, in my opinion they have been put together later from separate non-Heuer parts (dial and hands may be correct).

Unfortunately the "reference watch" in OTD has incorrect chronograph sweep second hand - http://www.onthedash.com/chronograph/reference-13-1-chronograph/. It should look as in this brochure: http://www.onthedash.com/wp-content/uploads/2017/02/1979P04.jpg

: Happy New Year to Everybody!

: Please have a look at this Ref. 13-1.

: Since we all know the Ref. 13-1 uses a Valjoux 7765 hand winding
: movement and not an automatic movement, I was a bit surprised to
: see the word „Automatic“ on the caseback.

: Could it be possible that this was an error made by Heuer or the
: case manufacturer?

: The engravings on the caseback, the marks of use all over the
: watch, shows clearly that the reference number was engraved at
: the same time as the other writing and not added later.

: So what do you all think about this?

: I am looking forward to read your thoughts.

: Thank you very much for your help.

: Greetings,

: Hermann

:

:

:

:

:

:

:

: