Kurt, if you can hang on till about 1030pm when I get home tonight, I have a reproduction of a Spit V manual that has all the specs on the Spit V, including tire dimensions and air pressure requirements.
the book is like a Chiltons manual for Spitfires, how to change the guns out of the wings, make repairs, electrical diagrams, landing gear parts, etc
It should work, I think if i remember right the Spit V and Spit IX are the same plane with differences in engines and guns.