hi ., thats the strangest west bend ive ever seen .. i have over 35 west bend 580s eight or ten 700,s and around 20 west bend /us 820,s never seen a taper crank on both ends .. specially on a left side engine CW rotation .. its deffinatly industrial engine and id almost bet only 2" bore so it be a 510 not 580 .. when you tear it apart messure bore if its 2 1/4 you have a 580 then its worth buying a 45.00 straight 3/4" crank .. plus if you put a 3/4 straight crank you can put almost any clutch on it .. west bend go kart /mini bike engines come with 9/16ths straight shaft very hard find a clutch reasonable ..
heres how id pop off flywheel but its me ..!! and not 100% correct way .. cant hurt the crank its junk anyways ..and cant use it in mini bike or go kart .. even if you swap out the the driver with #35 or #41 chain the clutch thats on its to weak for mini bike or kart .. find an old socket that fits in hole of flywheel and sets on end of crank bolt your puller on and run it up against the socket and pop it off .. kinda a two piece puller ..
when you get it tore apart let me no i can give you many leads on parts .if your interested ..