In a previous discussion about Venus and Valjoux movements, it was pointed out that both were owned by "Ebauches SA" -- thanks Roff.
viewtopic.php?f=11&t=15761&start=45I found an interesting article covering the history of this company.
http://www.watchtime.com/print-archive/In the keyword search put - ebauches sa
The article is called "WT_2006_06:History of ETA".
The watchtime databse has a lot of articles available for download and seem to be one of the few magazines who spend time on vintage watches.
Other articles of interest --
WT_2004_03: VALJOUX CHRONOGRAPH CALIBERS
WT_2006_02: THE HISTORY OF THE CHRONOGRAPH
The last article by Gisbert Brunner contains the tantalising line:
"The first patents for an hour-counter
mechanism date from the year 1892, but the
problem had only been theoretically conquered.
No tangible incarnation of a functional
mechanism appeared until 1937, when Universal
Genève was granted a patent (no.
1089191) on the corresponding technical solution.
Breitling launched a model with a 12-
hour counter on the basis of a Valjoux movement
blank in 1938. Other watch manufacturers
followed suit in subsequent years."