hmmm..apart from original plastics those 2 items (rh case and muffler) are probably next the most sought after parts for the 80B. Mufflers you'll really have to keep you eyes peeled on ebay and such. Sometimes a seller may list a pipe with the muffler in place not knowing it's value. '77 B /'78 C same part.
I've had the right side case welded. Cracking around the kickstart cast stop/idler gear carirer area is near 100% assured on all but extremely low hour examples.
Had a few welded by Bushell Engineering in Bris. northside.
http://www.bushellengineering.com.au/ with good results (but my 80's don't get flogged mercilessly like they once did
) When looking around also keep in mind the 80B engine numbers ran from 10001 - 23193
