The odd part is the tenons and sockets are black.
not just "wood" black, but they look kind of shiny black.
The bell you can see the "long streaks" of potential stain or something. And yet some of the toneholes are the same lighter color.
I wonder if this is a Chinese fake ??
I'd have to see it in hand to see for sure.
The odd part is the serial number with the K prefix. The K prefix was a Buffet made Evette-Schaeffer model or a more modern Buffet Limite(d) model.
I'm unaware of a "K" prefix in the E13 line.
But try using bore oil on the barrel and see what happens to the color.
Clarinets that are water damaged (think floods), then dried out Can look similar to this. But the tenons and sockets, etc would all have the same look. And the wood feeling would be grainy and rough. They can be brought back to life, very carefully. I had one from a flood and it took 6-8 weeks for re oil hydration to bring the wood back as it expanded and shifted around in light rounds of oiling. Then I let it sit for another 4 weeks as wood takes time to shift and stop shifting. I measured areas of the clarinet (outside and bore) too and noticed the wood changing shape, not visually but to a caliper and measuring tools.