Let me try to interpret our U.S. use of the King's English.

I am sure Dusty intended to convey that a Mark V having an older 3/4 HP motor and a one bearing quill would not be as good of a deal as a used Mark V having a headstock with a 1 1/8 HP motor and a two bearing quill.
1 1/8 HP motors are in all units starting in 1962
Two bearing quills were added in 1984 (?).
reference: http://www.shopsmith.com/ownersite/toolhistory.htm
P.S. I love your part of the world. Have called square dances in Calgary and have a number of friends up there.