Mike, where is the thread that Item 19 (bolt) screws into? Does it screw into Item 16 (pulley) - that is, does it screw into the shaft extension - or is it about a yard long and reaches up right through the shaft extension and screws into the end of the crankshaft? If it screws into the end of the crankshaft, by removing it you have freed the upper pulley axially, and it can be removed with a slide-hammer puller (though not with a screw puller). If it is a relatively short bolt and screws into the end of the shaft extension, we still don't know what is holding the upper pulley and shaft extension on the crankshaft. The diagram does not show any kind of pin etc, so I'm hoping you have a yard-long bolt that reaches right up to the crankshaft. You can check just by putting that bolt into the hole in the end of the crankshaft extension, and seeing whether it goes in far enough to be reaching up past the crankshaft extension and into the pulley hub, where the end of the crankshaft is, before it strikes thread.
