That guitar is a 25.5" scale.. I personally use 10-46 if I'm doing drop C or just whole step down on that scale. I feel the tension is pretty close to standard tuning with 9-42 strings. In fact one of my sweetest guitars is now set up with 10-46 strings in drop C. It is quite nice, but I might go a half step up and keep the same gauge, I'm starting to like the idea of a somewhat tighter tension on the strings.
So hey, it might not be bad to use 11-52 or whatever gauge is next.