Curbside Outtake: Three Trucks And A Riddle

Tom’s scale 1952 Studebaker from earlier today is downright neat—I pass one on the way to work that I think is of early ’60s vintage—I’ll need to stop and photograph it sometime. We’ve of course had a good bit of coverage here on CC on the International Comfovision cab (which the Stude’s cab reminds me of a little), but that has nothing to do with the answer to the riddle presented with this photograph, which is…

One can draw a line of connection between these three trucks (think “six degrees of separation”). Two of them are directly related (duh!), but what then links the third?