Scouts West

So I thought a 4th shift knob in a 75 Scout 80 was likely for a PTO but the owner told me that two shifters were for the 5 speed tranny. I know there were 3 5speed transmissions in Scout 80/800 but how would 2 shifters work? I've seen the oddball shift patterns with no mention of 2 sticks.
Thanks from a newb!

It's most likely an overdrive, which would give you one shift leaver, two leavers for the transfer case, and a forth controlling the overdrive. I've got a Saturn overdrive from a Scout 80 that looks like what your describe.

A '75 would be a Scout II, so I'm not sure exactly which vehicle you have.