I think fire trucks may have been available during the war. My father was a gasoline distributer and his brother sold cars. I remember my father and his brother talking about vehicles intended for essential industries being converted to civilian use and sold on the black market during the war. I'm not sure if fire trucks were on the essential list. If so, it would be reasonable to assume that they still used a 41 wire harness because all engineering went into the war effort. This is of course pure speculation. Our fire department is a volunteer fire department. County commission minutes would still be available here to see if a fire truck was bought during the war. However, if you ever want to sell it, It sure would be easier to sell with a good title in hand.