There is no doubt that the gun is post-WW2. The only possibility, I would think, is that
the K was omitted, for some reason or other. I've never heard of that happening, and
the probability is very very low, but its still possible.

I, and others, would like to see a picture of the butt, and the rear face of the cylinder. I doubt any of us have ever seen a post-WW2 .38 target, this early, without the K in the
serial number.

Regards, Mike Priwer