The fol URL takes you to a document about the Halifax Concert Party, a civilian org that entertained the troops. Strangely, the article mentions the use of a HUP (para just above the first photo) to haul a portable generator plant. In my mind, a not so noble task.
So, some HUPs indeed had tow hitches attached...I wonder if they were the bog-standard pin hitches or the real deal spike type military hitches???
http://www.lib.unb.ca/Texts/TRIC/bin...me=oneill.html