In 1970 I saw this old guy on top of a pile of scrap metal in one of the Wendover hangers. I asked a young kid there, "Who is the old guy on the pile?" "That's Bert Munro!" I had heard about him so I asked, "What's he looking for?" "A flat plate to make a new sprocket!" Blue it, scribe it, drill x number of holes and file each tooth by hand!
Now I am the old guy hanging still around the salt!
And no, I won't make your sprocket for you!
But these guys will give some good leads!