You can do a little process of elimination and avoid some of this seemingly contradictory guessing by measuring the bolt circle of the axle studs. It looks to be fairly "tight", but then my calibrated eyeballs are as well calibrated as they once were. Anyway, if it's a 4 1/2" circle that eliminates GM, if it's 4 3/4 that eliminates Ford, Mopar, AMC, If it's 5", well back to the drawing board. If it's a 4" circle it's small Mopar such as Dart/Valiant.

Is there no tag on it with any kind of numbers?

Edit: Must be Bobs on a wavelength day.