Mack Hils did a book on '32-'47 Ford pickups that included a lot of factory photos from the Ford archives.
As for the heater--even the correct Ford heater was a dealer installed option, most optional equipment back then was dealer installed. There were dozens of brands of aftermarket accessory heaters back in the day sold through service stations, garages, auto parts stores and retailers like Sears and Montgomery Ward. Harrison, the GM subsidiary that made radiators and heaters for GM cars, went after a piece of the aftermarket pie as well. They sold the same heaters that got branded with the various GM brands through the aftermarket under the Harrison name. Most people back in the day bought one of the aftermarket heaters instead of buying one from the dealer. So, if you're building the truck to be a enjoyable driver rather than a Dearborn Award contender, the aftermarket heaters are plentiful and affordable. I have a Hot Wave brand in my '38 pickup. works great.