The great thing about this hobby is that it allows my OCD to really shine. In this section, it’s all about the dial. A specific dial seen on Omegas (most often Seamasters), with cropped 3, 6 and 9 numerals. More details on these watches, and others, can be found on the Omega Cropped 3-6-9 movement number project page.

Omega CK 2451
The CK 2451 was introduced in 1946, and utilized the 27 CHRO C12 T1 and 27 CHRO C12 T2 movement, renamed as the 321. The 27 refers to the diameter of the movement in millimeters, ‘CHRO’ to the fact that it has a chronometer, and C12 to refer to the 12-hour counter. This co-developed project began in 1942. The 321 ended its initial production run in 1968.
Omega provides sparse notes on the CK 2451, only that it has a dial with inside tachymeter scale (though that is not the case for the CK 2451 dials in the Omega Cropped 3-6-9 movement number project), and caliber 321 (though not all are stamped as such, coming from earlier in the 321 lineage). We see two square lume marks at 12. Note we do not see ‘Seamaster’ in the dial. Alpha hands are radium filled (except as noted within the project).
Omega Seamaster CK 14364
The Seamaster CK 14364 was introduced in 1959, and utilized the Caliber 321, the evolution of the 27 CHRO C12 T2. Sparse Omega notes indicate that the CK 14364 was produced with a stainless steel screw-in case, and luminous (radium) dial with hand riveted solid gold hour markers and “index” hands. Water resistance was to 30 meters. As with the 2451s above, we see two square lume marks at 12.
The dial on these CK 14364 is the same as seen on later CK 2451s as above, not surprising given that this followed CK 2451 production.