I personnaly am a great fan of mono pusher chronographs, they have an amazingly pure look, and one of my dreams would be to commission VC to make me a single pusher chronograph!!
VC like almost all brands offered monopusher chronograph wrist watches until the mid 30s when the 2 pusher chronograph was invented (by Brietling)
Today not many brands offer a chronograph with a single pusher but rumor has it (and don't quote me here) that Vacheron Constantin may offer this implementation sometime in the near future!!!
Three types of monopusher chronograhs exist:
1) The start/stop/reset button placed between the lug and the crown
circa 1915 (probably one of VCs first wrist watch chronographs, at 38mm diameter it is most certainly a pocket watch to which lugs were subsequently soldered note the original type "lugs" or "links")
2) The start/stop/reset pusher placed coaxialy in the crown
Made on special order for the English Crown and presented by King George V to Admiral Richard Byrd in commemoration of his 1926 Arctic Expedition. This watch is probably unique and measures an impressive 45mm in diameter. Sold by Antiquorum in 2005 for 226,250 Swiss francs!
cushion shaped chronograph from 1930 made in only 10 pieces. sold by Antiquorum in 2003 for 146,500 Swiss francs
Made in 1928 for Alexandre I King of Yugoslavia (was the thinest chronograph of its time)
3) the start/stop/reset functions are controled directly via the crown
...would you know if that is for a "normal" chronograph or for a model with other complications?
available I don't see why extra complications would not be added.
a regular 2 pusher chronograph!