In the late 60's and early 70's Gleaner combines (Allis Chalmers brand) had a rather goofy "power steering system" on the E,G, and maybe early F series combines. The steering box was manual, with a hydralic slide valve steering cylinder mounted down at the rear steer axle for the "power part of it". The point being, the manual steering box has a real long sector shaft. Long, as in around 18 inches long. More than enough to get it out past the cowl, and still center up in the cab for the steering column, steering wheel position. I tried to get a picture off the net, but can't seem to come across one. The C, E, or G models would have used this box, it changed right around the F model (early 70's) to a hydralic orbit motor/pump style, so the manual box was eliminated. Even though the age is getting up there, the box will show little to no wear. Combines are only used a couple of weeks per year, certainly not going to wear them out. They are easy to spot, under the cab the floor area was open. A quick look would confirm if you have found one. I've been looking for one myself, just haven't come across one yet. Sniper