That your was the first iteration, ie 2938-1. On most Omegas iteration number is just a curiosity. Only on the super collectable stuff like early Speedmasters does it truly matter. There 2915-1 is worth way more than 2915-3 for instance. Some popular models like the 2577 have up to 20 iterations. Often there is no discernible pattern as dial variation doesn't always follow iteration.