A Guide to Vintage Panerai - The Luminor 6152-1
Italian brand Officine Panerai made watches for the Italian Royal Navy around the start of the 20th century, and the surviving examples of these are very collectible for fans. After about a decade of selling the military the ref. 3646, the navy asked the watch brand for a more heavy-duty version of a diver's wristwatch, and the ref. 6152 and 6152-1 is what Panerai came up with.
This model is often called the "Luminor," after the luminous substance you see on the hands and numerals that Panerai patented in 1949. Luminor replaced "Radiomir," which was the lume that was developed between 1910 and 1915 (The Radiomir nomenclature is still used to mark Panerai watches today). There are only about 100 of these watches known to be in the World today, which makes them especially hot. Some were produced with crown protectors, some without and some with either Radiomir, Luminor or Marina Militare on the dial.
The case and movements were made by Rolex, and this example bears a signature by Rolex on both—as well as rare military markings engraved on the back of the case. (Watches supplied to elite warriors like froggers, torpedo riders, and commanders of the Italian navy bore the "Marina Militare" insignia on the dial, as seen here.) A bulky crown protector on the side of the cushion-shaped case is an additional flourish.
Only a handful examples of Ref. 6152/1 featuring the famous crown-protecting device that retained the original Radiomir dials have survived. Most of these watches were updated with Luminor dials at some point in time. The luminosity in radium-226-based dials had a lifespan of only three to five years due to the deterioration of the zinc sulfide. Since these dials had to be replaced periodically, the most plausible explanation for the existence of watches that retained the original Radiomir dials is, they were unlawfully taken out of service at some point (stolen).
The explanation for the existence of Luminor dials in Ref. 6152/1 watches without crown-protecting device is pretty simple. In these cases, the original Radiomir dials were replaced with modern Luminor dials at some point after 1965. As mentioned, the luminosity of Radiomir dials lasted only three to five years and the dials had to be replaced periodically.
