If you are asking if all Model 14-1s were made as SAO, the answer is no. Without some form of legitimate provenance, as far as I know, there is no way to know how it left the factory.

I have a 14-1, and when I purchased it, it was a double action revolver, just as I supposed it would be. I lettered it and found that it was ordered and shipped as a SAO variation. At some point, the SA hammer was replaced with a DA hammer. But without that letter, I would never have known the difference.

Early on, S&W sold SA hammer/trigger sets in a blister pack that anyone could purchase and swap out the DA parts. Again, without that provenance (proof), I know of no way to tell whether a Model 14 left the factory in SA or DA configuration.

__________________
SWCA 3297 SWHF 583