PAUL - I just checked Charlie's site, He does have a bunch of snow blower parts. I bought a new chain adjuster casting from your local C/IH dealer many years ago, two new needle bearings, a sprocket, think the shaft was O-K, couple roll pins. I paid $90 for the QA-36 blower and my little box of parts was over $150, the casting alone was almost $100.
Another place to look for a pulley is MOTION Industries, and make sure you get the right width keyway, I think it's 3/16ths inch, and to handle the horse power it should be cast iron, diecast or stamped steel won't hold up.