The one with the boggie assemble nuts, what is the goofy roller bearing for? .
The Snow-Trac final drive chain is ISO metric size 16B-1 that is 25.4x17mm. (pitch 25.4mm, roller width 17.0mm) This is close to the ANSI #80 chain as it has the same pitch, but the 16B-1 is slightly wider. If you put ANSI #80 chain on a Snow-Trac it will chip the final drive sprocket teeth on the sides. Not a good thing.
Post #4 : http://www.forumsforums.com/3_9/showthread.php?t=12689
rare lock washers for the spanners I would give up a left nut to find a source for.
Try your "local" SKF rep/dealer.
Try your "local" SKF rep/dealer.