Audemars Piguet Quantieme Perpetual Calendar ref.25657BA Full-Set from 1980s

The model 25657, which was a predecessor of the reference 5548, was manufactured between 1982 and 1993. This particular model embodied the characteristics of the earliest pieces of the Quantième Perpetuel, introduced by Audemars Piguet in 1978. It boasted a slim design, being the thinnest automatic perpetual calendar at the time. The watch featured a timeless combination of a yellow gold case, a crisp white dial, and the distinctive "Audemars Piguet" signature. It had serial numbers falling within the C and D series. 

The dial of the Ref. 25657 had notable sub-dials positioned at 12, 3, and 9 o'clock, with a sunken appearance and inner black strokes. The dial was marked with the phrase "Swiss Made," and some later versions displayed the updated capitalized 'A' and 'P' logo introduced by Audemars Piguet during that era.

A total of 1821 pieces were produced, with yellow gold being the most common case material (1309 examples). Other variations included 362 examples in pink gold, 128 examples in platinum, 16 examples in white gold, 5 examples in two-tone, and only 1 example in steel.

Brand: Audemars Piguet
Model:  Quantieme Perpetuel Calendar 
Year of Manufacture: 1980s
Serial Number: 25657BA
Material: 18K Yellow Gold
Dimensions: 36 mm
Crystal Material: Sapphire Glass
Movement: Audemars Piguet's caliber 2120/2800 automatic movement
Buckle: AP 18 Yellow Gold Buckle
Box/Papers: 5 piece full-set with open warranty papers.
Mechanical Function Guarantee: 6 months.

comments: The perpetual calendar setting pin is Chopard, the original owner mixed the setting pins and consequently lost the AP setting pin over the years. The watch is in unpolished and unmolested conditions.