How much information can be discovered from the serial # on a HP 70 standard?  The tractor has headlamps, pto, and electric start but is on cut off steel spokes.  I have a picture of this tractor from 1937 and is shown to be on the cut offs already and shown with headlamps.  We spoke with one of the gentelmen from the dealership that sold this tractor to my family in 1937 and he said the steel wheels were cut off right away and he seems to think the headlamps were added either at that time or later but was not sure.   

Is there info on the options and build date for serial #301556

Thanks!