Marty, restoring my axles & wheel studs & thought I would post this picture. One axle had five studs with triangle stamping the other had "F" stamping on the studs.
Studs are all same length, "F" studs have slight taper at the start of the thread for maybe 1/16". All were black phosphate finish before glass beading.
Both axles seem original but I don't know for sure. Maybe others can post what they have seen. George.