If the brakes and steering and the rest of the mechanical components were in good working order, I don't see why not. Maybe not in rush hour traffic in D.C. where commute to! I don't know about the 3 speed but Tim is way more knowledgeable here than I am. I suppose it would also depend on how heavy the trailer is, plus a 1000pd hay burner.
I can't imagine this wasn't a common job for these trucks back in the day. 2nd the no bumper pull hitch. There isn't much I would pull with one of those.
Would love to see them done up together.