You're right. I have an email into Bicycle-engines to see if that crank shaft is the tapered one. It doesn't look like it when you click on the larger pic.I can't speak to wether or not the parts are interchangeable between Honda and HS motors, but bicycle-engines has the HS parts you mentioned and shown on their web site. Which usually means that the parts are available from them? 49cc Engine Parts (crankshaft), 49cc Engine Parts (side cover)
ocscully