Is the 1974 Barth Class C, a 30 amp or 20 amp coach? I think that the shore cord is a male/male cord that plugs into a female outlet in a small exterior compartment that has two plugs, one for the generator and one for the shore line. I guess you store your shore line somewhere else because the compartment is too small for much of anything. This is a 19' Class C.
BTW, I have a faint memory of a rather interesting discussion of male to male shore cords. Just faint--no details.
Jim

Our 76 class C has a 30A 20' shore cord that stores in a small compartment above the gen. It plugs into a 30 amp receptacle that is the output of the genny. mounted in the same compartment.