An outlier on this site of primarily vintage wristwathces, I have found myself strangely attracted to the Audemars Piguet 5526. This deep dive is focused on the AP Grande Complication from approximately 1960 through the mid-1970s. I originally began looking at just the AP 5526, but have expanded this overview to include the AP Grande Complication 5543 and like timepieces, simply as I prefer the design of these Audemars Piguet Grande Complications as a group, though the calibres differ.
The AP 5526’s Cal 17 JSMCCRVQ combines a number of complications: hour, minute, small seconds, perpetual calendar, day, date, month, leap year, moonphase, chronograph, split-seconds (rattrapante), and minute repeater. We also see a unique piece, which appears to be based upon the AP 5526, also utilizing the JSMCCRVQ.
With the AP 5543 (BA) we see with the Cal 18 SMCRQV.