These K prefix Pythons in 1980 were labeled in a couple of ways, this being one of them. If I were paying $10,000 for a scarce Python, I would prefer to have a nice and tidy computer generated label. But, this configuration of Python is rarely seen and this Label is legit. This is one of the circumstances where the box and label might be a little less important for the collector than say a NIB, 1980, 6", blue Python.
Do you have photos of the Python and is this an opportunity for you?
Only 23? That's pretty cool. I had read that the 3" guns weren't introduced till 82 but Colt put out a few in the is time frame to test the water. The gun isn't 100% but after I get it home and cleaned up I think its a solid 98-99% only due to some minor swirls. We'll see. Where did the 23 number come from?