In Reply to: Re: Alum hood tractor in sale posted by Steve Dabrowski on November 10, 2017 at 22:08:42:
The hump on left brake, Riveted axles flare at bottom casting at the top link on the housing, see photos,first 39 then later housing. Also the bottom of the leveler arm were it connects the the lower three pt arm is beefed up with the stop on top not bottom also an indicator of a later style.
close up of '39 and '40
If you go to the auction good luck.