November 26, 2022

So I was just reading something and am a little confused, hopefully someone can shine some light on this because the rest of the internet is being incredibly unhelpful. The first AP perpetual calendar, the 5516. The first time I saw it, it looked like this:

BUT in the Christies November 17th, 2008 Geneva sale, they had a 5516 that looked like THIS:

So as you can imagine I am confused…because they are definitely different haha
Does anybody know about this?Did Audemars make two different 5516’s? Cause that movement would be totally different even just based solely on the position of the moonphase.I cant imagine the first picture being wrong considering as how it came from Michael Friedman.Although at the same time I cant imagine Christies being wrong on this one either seeing as how this lot raked in a cool $315,000.Any knowledge would be greatly appreciated.
Regards,Dylan T. DutsonHi Dylan, 
Well, you’ve picked quite the reference to zero in on – the ultimate vintage AP to be sure. 
It is my understanding that there were only eleven 5516s made, all in 1957. Not all of them featured a leap-year. Of those that did, six have the moonphase at 6 and three have the moonphase at 12. The watch you show from M Friedman is certainly a 5516. 
The watch sold by Christies is actually a precursor to the 5516. Three of these were made, in 1955, and they had no reference # at all. As you may guess, the 5516 is a direct descendent from this (basically unique) predecessor. Both use the same base movement though – this “no reference 5516” ticks on a Valjoux13 VZSS while the 5516 runs on a slightly modified Valjoux13 VZSSQ. 
To say that the Christies’ watch is rare would be a massive understatement. These are virtually unique, and I believe only 2 are currently known to still exist. 
I hope this helps,