Need to know about my Railmaster

Also, ‘prototype’ is a difficult term to use correctly with vintage watches. I’d say (and other May disagree) that a prototype is a watch that doesn’t make it to market. It’s produced in very low numbers and circulated internally within the Omega head office and Distributor network, but not sold to the consumer.

On the other side, any watch that is released for sale even in small batches (and there are multiple examples of very small batches of Omegas in the 40’s-60’s) is not a prototype, but simply a small production run.

Just like the Seamaster already existed prior to ‘57 and was significantly upgraded as part of the trilogy to form the SM300, the same seems to apply to the Railmaster. The only difference being the function didn’t dramatically change as with the Seamaster and nothing was added to the name.