It sounds to me that the plow in question is not a Plowmaster with the comb type lift. You refer to the lever as it goes into the casting on the land wheel.  This indicates to me it is a model 214 or in the 1940s we called this the Heavy Duty plow. This type lift always used a rope pull, typical of most other makes of plows.  The Comb lift normally had a rod with a ring(loopP at the end and on many tractors no rope was needed. you would just reach this rod from the tractor seat. 
If I am correct, you will need to pull the land wheel off the axle and proceed to dissassemble the clutch type lift assembly.  Sorry, I can't remember any details on the inner workings of this type lift.