Steve M. Welcome to IHCUBCADET.COM. Steering brakes were an option on 982's. As were the Cat. 0 three-point hitch, rear PTO and aux. frt Hydraulic outlets. Supposedly all those options were a "Package Deal" so since You have the steering brakes You should have the rest correct? There actually aren't too many that I've ever seen without the brakes, 3-pt, rear PTO & aux. hyd. but they do exist.
I'm not exactly a "FAN" of the 20 HP Onan, they're getting real hard to find parts for and Nothing I've ever found for those engines is/was cheap. On the pulling forum here there were some posts about a year ago about dropping a Generac engine into them, or a Honda, Briggs & Scrapiron, maybe even a Kohler twin if You want to spend the $$$$$.
If the tractor itself is in decent shape, with all the options, paint, sheetmetal, tires all O-K $400 was a bargain.