The 145.022-69 and 145.022-71 dials have the step dial, easy to discover as it divides the main center part of the dial with the outer part where the minute track is printed. This flange disappeared with the 145.022 replica watches.
Basically, the dials of the Speedmaster Professional 145.022 replica watches can be divided in two different variations. The step dial and the flat dial. The step dial comes close to the dial of the 145.012 and its pre-decessors, except for the differences in typography and the applied Omega replica watches logo (except for the transitional 145.022-68 reference).
After having checked the movement (also make sure to look at the gasket, are they still ‘like silicon’ instead of hard and plastic like which indicates the Omega replica watches haven’t been serviced for a while), have a look at the inside of the caseback for inscriptions. Besides the 145.022-XX indicator, some times you see some indication that the Omega replica watches have seen a couple of services.
Anyway, this number can be checked with high quality Omega replica watches using their Extract of the Archives information. If you are not willing to spend CHF 150 Swiss Francs on that, you can use some of the tables floating on-line to get a rough estimation on the production year.