I picked these two Gen Rivet Bracelets up to help in that effort. the 6636 / 7206 are the 20mm bracelets to have. They made Swiss (worth alot more) and USA CI bracelets.
Top - Rolex Pre 6636 with rare 64 End Links. End Links are for Big Crown Model Subs. The have concluded the Pre means Pre-Stamping of the bracelet number on the last end link.
Bottom - Rolex 7206 with rare 58 End Links. End Links are for Big Crown Model Subs.
6636 on left
7206 on right
6636 - Date stamp of 56.
7206 - Date stamp on a middle clasp.
7206 - Date stamp of 69
6636 are expandable bracelets.
Top - Rolex Pre 6636 with rare 64 End Links. End Links are for Big Crown Model Subs. The have concluded the Pre means Pre-Stamping of the bracelet number on the last end link.
Bottom - Rolex 7206 with rare 58 End Links. End Links are for Big Crown Model Subs.

6636 on left
7206 on right


6636 - Date stamp of 56.
7206 - Date stamp on a middle clasp.

7206 - Date stamp of 69

6636 are expandable bracelets.
