If you can't find one, I might be able to chop mine apart and weld it to the crank arm.
But, that's a big "might." The sprocket is welded on both sides of the shaft, which is a lot of grinding, I'd have to get it lined up perfectly, mine is rusty so it'd have to be rechromed if that's what you're going for... Etc...
it could be done, but I'd have to charge you more than a new one costs. (edited)