I had completely forgotten about this thread, and I am glad it came back so I could study SmithNut's first-rate K-38 photos all over again.
Perhaps the only distinctive type of K-38 not already represented in this thread is the very early type with the large ejector rod knob. These guns were barely on collectors' radar screens at the time this thread was first live, but in the last couple of years a few have been posted and discussed here. I have K4709, which was featured in a recent thread about the LERK Masterpiece models. A pic:
I believe no more than 350 K-38s were produced with the large ejector rod knob; only five have been reported on this forum, though members may own a few more that have not been discussed. All others almost certainly carry the knobless rods seen in the other photos in this thread.