Check out this Rolex ref. 6154.. Look familiar? I didn't mention it in my post the other day, because only a few got made. It was the thinnest Panerai of the era, with thinner (but still 2 layer) dials. They switched back to the thicker one pretty quickly though
These Rolex have the same ref number, but only 6 are known to have been sold in the 50's - I guess the rest went to Panerai.
This one got sold 5 years ago for like $250K. It was still 47mm, which I assume means it was bigger than just about any other watch you could buy at the time. I don't know if these 6 watches ever made it to the commercial market, or what...
What's interesting is that this Oyster Precision watch has the Submariner dial, which was introduced the year before... So it was a quite outdated dive watch already (this one had the same manual wind movement as always, while the Sub had an automatic)
Speaking of the dial, where did the design come from? Dive watches were just starting to come out, and while Panerai was the first to design dials specifically for diving, Rolex did a more modern take... In fact it was adapted from their "error proof" dial going all the way back to the 30's (and some Panerai models used these dials during the Nazi occupation, as seen in another post I made with the anonymous version)
This is a late 50's version, since it has an automatic movement. Allegedly, these got really popular in Japan during the 80's, and watchmakers in LA catered to them by restoring these and marketing towards rich Japanese tourists. Since then, they were commonly referred to as having a "California" dial, rather than Rolex's own name for it "error proof" (referring to the high visibility, and marker at 12 to aid in orientation)