Hi, I have a pair of UPZ R 10 for sale on this site. I list them as size 8, because that is the size I told him I wanted when I ordered them, because I didn’t want a loose fit.
The liner is stamped 6 1/2, which I assume is 26.5. I also wear 9 US, and they worked fine for me.
You can check them out and let me know. I also have two Donek boards with CATEK bindings that I am selling, but haven’t listed yet, one is 162, the other 158.