My 1970s Wolseley 27" Self-propelled Grasscutter has been an extremely useful machine since bought in 1986 -- but now it needs thorough renovation. All is dismantled bar the main pulley drive through to the blade connections, which are all on a vertical shaft about 12" long. The shaft emerges through the top of the main pulley as a large threaded bolt. The pulley has a central hard-steel collar with a key slot. I cannot work out whether the collar is welded to the pulley core and so the pulley unscrews, or whether it is part of the central shaft and the pulley should be removed with a puller. I have applied heat and force in both ways without result except that the large puller I have used is distorting the mild steel pulley.
Is there a parts diagram out there that would give me the vital clues? I would be very grateful?