DRSD Casebacks

The Double Red Casebacks — three documented types across the full production run, including one that surprises even seasoned collectors.

I have only seen three types of caseback on most regular production Double Reds. Each type corresponds to a different phase of production and carries specific markings that are essential for authentication. Getting the caseback wrong is one of the most common mistakes in the DRSD market.

The Three Caseback Types at a Glance

The Standard “Rolex” Caseback

The regular production caseback carries the word “Rolex” engraved across the back in the standard Rolex script. This is the most commonly encountered caseback on Double Reds and spans the bulk of the production run. It is flat in profile — the defining physical characteristic that separates it from the rounded Type 3.

The Patent Pending Caseback

The early production caseback carries “Patent Pending” text on the exterior — directly corresponding to the Patent Pending dial variants. This is the rarest of the three caseback types and is exclusively associated with the earliest production Double Reds.

Type 2 — The Patent Pending caseback exterior. This early production caseback directly pairs with Patent Pending dial variants.

Interior Caseback Engraving

Inside the caseback — on all three types — the full serial number or last three digits of the serial should be engraved, along with the model number 1665. This interior engraving is one of the most important authentication points on the entire watch. It must match the serial number on the case.

Type 1 standard caseback exterior — “Rolex” engraving, flat profile.

Interior engraving — full serial number and model 1665. Must match the case serial exactly.

The Rounded Caseback

Now, I know what you are saying — the DRSD did not have a rounded caseback. Well, contrary to some of the mainstream knowledge, some correct Double Reds were born with a caseback usually associated with the White Sea-Dweller.

The reason we know these are correct is twofold: they were purchased from the original owners in that condition, and secondly, all had the full serial number engraved inside the caseback — documented as high as 5.2 million. So yes, the rounded caseback is a legitimate DRSD caseback.

Type 3 — The rounded caseback, confirmed correct on Double Reds up to 5.2 million serials. Usually associated with the White Sea-Dweller, but documented as factory-correct on a number of original-owner DRSDs.