Phillips worked with Audemars Piguet's archivists to confirm that this is, in fact, correct and all original.
The catalog notes show that this example is hiding a few interesting details as well, most notably a serial number for the case that's stamped on the interior of the caseback. It has a Mark 1 dial, and no leap-year indication, two easily identifiable features of an early RO QP. The final QP I want to highlight here is lot 54, a four-digit example that dates to 1985, the second year of serial production for the Royal Oak Perpetual Calendar. That's 30 percent of the catalog! These are five of my favorites. Just think about this – in this Phillips catalog, which is purportedly meant to include as many of the rarest and most desired Royal Oaks ever made, there are 27 lots featuring a perpetual calendar (including the Grand Complications). We had a Royal Oak QP nearly a decade before we ever saw a Royal Oak Chronograph, and 13 years before a Royal Oak Tourbillon.
Now, I'm not going to dig into the entire early history of Royal Oak Perpetual Calendars – James already did that two years ago in tremendous form – but it's important to understand just how significant the perpetual calendar complication is to the Royal Oak identity.
5548 (AP would soon switch to a five-digit reference number format) utilized the 2120/2800 perpetual calendar movement, a stunningly slim self-winding caliber with, and this will be important later on, no leap year indication. The first Royal Oak Perpetual Calendar was officially released in the mid 1980s, approximately 12 years after the birth of the Royal Oak.