Ok I never figured out how to get that pulley off in order to access the crankcase, and I didn't have to (at the moment). I unbolted the side cover and the whole guts just came right out. I found the cap, retainer, & missing bolts (one still completely intact):
I also discovered that as the rod broke apart, it snapped the camshaft. I thought the cam was ok because it still spun the rods up and down as I turned the motor before disassembly. I guess because of the angle of the crack it was still able to grab itself and spin with the case supporting and surrounding it:
