You don't need a torque wrench to get you out of this pickle. Swap a new pulley on and do it up nice and tight. If you need a replacement pulley I might be able to rustle something up but if you call Berry Motor Group in Melbourne and ask for Mark (@iceton1975) he will almost certainly be able to express post you a replacement.
Shade-tree crank pulley removal/refit process:
set the engine to bottom-dead-centre (BDC) on the #1 compression stroke, remove #1 spark plugFeed rope into the spark plug holeTighten up crank pulley bolt until engine starts to turn over. The piston will come up and jam against the rope and you can tighten the crank bolt up.To remove the rope, back the engine off a few degrees and pull it out.
If you're trying to loosen the crank bolt, the process is the same but obviously you need to start at the end of the combustion stroke at BDC, put rope in, then wind the motor in reverse until it jams against the rope. The stroke does matter because you don't want the rope to be getting wedged against an open valve. To find the compression stroke, turn the engine over by hand with your finger over the #1 spark plug hole. You'll feel air pressure under your finger as you bring the piston up on the compression stroke.