I'm not sure about gear reduction steering.
I remember my 1987 WH 416-H steered a little harder than my newer 1993 WH 416-H.
I'm pretty sure they both used the same steering gear set-up, the only difference was the 1987 WH had a noticeably smaller diameter steering wheel.
I actually preferred the older, smaller steering wheel. The larger steering wheel made it more difficult to get on and off the tractor.