Patek Philippe 3603

A bit shocking at first sight. It begins to make more sense when taken into context as part of the "Collection". My mockup below.

The Patek Philippe ref. 3585 has had multiple variants, among which some had an electric blue textured dial with ‘ x-strokes ’ or crosshatch or crossed shard-li

Patek Philippe ref. 3603, powered by the quartz caliber Beta 21, was released in 1973. Nicknamed the ‘Grande Ellipse’ it stayed in the product line until 1983,

Seen tonight off the wrist of a friend. I was wondering if anyone could shed some light on the reference number and what this is? I was told some, but thought I