That's the Rolex paradox. Even though the evolution of its designs has been extremely slow, and even though most of its fans love the old and familiar, the company is perpetually at Year Zero. Rolex won't lift a finger to verify a vintage piece, and is downright hostile when it comes to supplying parts. "Sorry, we can't say a thing about your 1680, but wouldn't you rather have this cool ceramic Sub?"
Anyway, I leafed through a friend's copy of Vintage Rolex Sports Models and took the following notes. I know that Skeet/Urul aren't gospel, but they do have their merits!
There were four versions of the 6610, all of which were gilt/gloss-dialed, and all of which were marked OCC:
-V1 had a red depth rating and pencil hands, similar to the earliest 6200-series Submariners. This might be what the guy on VRF meant.
-V2 was the same, but with the familiar Mercedes hands. Note that most of these hands were of the long-neck variety, which may also be what VRF guy meant!
-V3 is the same as the previous type, but without the depth rating, and with a sweep hand painted white.
-V4 has a honeycomb dial, similar to the ones found on the 6350.
Furthermore, 1016 is noted as being the first Explorer with SCOC markings. However, this is contradicted by a lot of stuff that has already been noted in this thread. Someone on TRF asserted that the change from OCC to SCOC happened in '57, but I don't know if you can draw a clean dividing line through that year. However, I remain pretty sure that you would not have seen a matte dial Explorer in the 1950s.
