This snowblower is serial number 59750-1679. It is the large two stage machine made by Jacobsen.
Specifically, I need auger end shaft bearings, the ones that fit on the outside of the main housing with three bolts. Two lock screws hold the inner race to the auger axle. The bearing unit appears to be in two parts which are pinned together and hold the bearing balls.
It is possible that these bearings are common to other makes or standard for the time but I have not yet looked into that.
The Snowblower has been run for 15 years or so with my Chief 800 and works fine but it is time ti address some wear issues before I have to do it at 10 degrees below zero.