Rings are easy. Contact Dave at Otto Gas Engine
works. Standard ring sizes are $5.00 + $.50
shipping each but he can make you what you
need if they are oddball. I doubt a decal is available
for your Super Single but I’m wrong enough that
there is still a chance. The prop may be a challenge
however Doug & Matt Penn are amazing at finding
parts for these old motors so give them a try. Here
are some links.
Tubs
http://pistonrings.net/rangcast.htm.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.