I'm going to replace my sprockets and chain in a few weeks, and so I re-read Mustang's How-to, but couldn't find specifics for the aftermarket part numbers here on the forum. So, I dug around the web and here they are for future searchers:
Front sprocket - JT Sprocket model JTF-1180 (18 tooth)
Rear sprocket - JT Sprocket model JTR-2010 (48 tooth)
The 18t and 48t are the stock gearing, and work just great in all of the terrain I have ridden. YMMV?
Chain size is 530 with 114 links. I bought an RK 530GXW to try this time. I bought a Scottoiler at the Triumph National Rally in Oley last year, and have been waiting to install it once I installed the new chain and sprockets. I expect to get lots and lots of miles out of this set up.
Pretty pleased with the cost for the chain and two sprockets - $202.98 with free shipping from Amazon Prime. The master link comes with the chain, and it is a rivet type. I have an RK chain tool, and would highly recommend it if you don't have one. Works great.
Yea you are running exactly as JT recommends... :thumbsup