that's a tough one
although i have managed to aquire 2 kd-12 models and even find a pump seal for them thru hobart i have never come across anything related to a kd-10!
maybe someone here on the site can offer you some insight.
if it's a good price i would say grab it whether it runs or not! it was hobart's first model, i believe in 1949 so it is definately a keeper! you could always turn around and sell it later if you decided to! i would love to have a kd-10!
good luck!