It kind of looks like one of the two hitches used with a one wheel trailer. Wards and Sears sold them in the 40's through 60's. Maybe longer, but you don't see them much anymore.
chopo: Take a look, there isn't very much holding Model A bumpers onto the brackets. The hitch is going to have to be mounted to the frame as are the bumper brackets, unless you want to install it as a conversation piece only. JMO
Paul in CT