Coming into the 80s perfect replica Audemars Piguet had its sports line, lead by the Genta designed 5402, but also its dress line, lead by the Dimier designed 5548. The latter used the ultra-thin perpetual calendar calibre 2120/2800 which was born from the addition of adding a perpetual calendar module on top of the original calibre 2121. It became the world’s thinnest automatic perpetual calendar, and was kept very separate from the Royal Oak, which by comparison was simple in complication terms. In 1984 however, the two forces joined as UK high quality copy Audemars Piguet chose to insert calibre 2120/2800 into the case of the Royal Oak to create…