Thanks to all the great advise from friends here, I recently added a second perpetual calendar to my small and humble collection; this particular piece is about 15 years old; comes as complete package in great condition from a good friend of mine; love the warm, vintage look of yellow gold; I adore the smaller 36mm size which perfectly fits my small 6 in wrist; it does contrast very sharply (albeit in a nice way) to the more sporty, modern, and somewhat sterile look of my 5550P. Here is a quick comparison pic for your review.