Looks like a special running board with the parking brake.
Were these tractors part of an auction, but no-sale'd? Maybe
the high bid can be found out. At an auction this month, the junkiest
tractor went for $250. [it had a $400 injector pump] Whether to repair, depends on how cheap you work, or if you do it as a pleasure. $1500 for tires, rim work, seat, correct grille or hood. $3000 for engine
repair. Auction price around $4000-$6000. On the other hand, with all
the bother, might make $1,000 parting it out, given enough time for buyers to show up. If I had the time, I'd like to fix it up.