MYRON - On those old ROSS diecast steering gearboxes I find most of the looseness in the steering comes from the top thrust bearing race collapsing or distorting and working it's way up inside of the steering tube and causing the problem Larry mentions. On the old gearboxs off the 72 and the 129 I sold last summer I installed a 1-1/2" OD X 3/4" ID steel ring inside the tube to back up the upper thrust bearing retainer to prevent that from happening. On the old box off the 72 even with that repair after about 15-20 years the steering shaft would back up OUT of the steering tube about 3/4 inch when You turned the correct way, I forget if it was left or right. When I priced a new threaded stud to engage the steering worm about 25-30 yrs ago and found out how much they cost then (over $20) I did some fine work on the old one with a file and a grinder, IF You tighten them in too far they bind up the whole gearbox and lock them up at tighter turning angles.
Larry need to watch His steering shaft where it comes up out of the steering tube to see how much verticle movement the shaft has as He turns His steering wheel. The steering worm and stud are both hardened and very little wear actually occurs, especially on the worm since the stud runs almost the entire groove.