I have a 1973 International and the body was made by Grumman. Sorry that I just saw your post. I haven't had much luck getting info on my RV, but I can share some of the manuals.
hi Dee. don't feel bad i inherited a " title says" 1974 1310 MHC IHC home. all i can find on it ,is it was built in Chicago, then discontinued. also like another person, my left rear brake froze up so bad that i had to cut the drum off. this thing has been nothing but a pain. but i will keep it, as i might have to live in it for a while. good luck to you. mike h.