I thought you might have a que of would be builders at your door wanting a set of castings after the article.
I seriously considered starting a casting kit company at one point, but when you get into the logistics of it, it is not practical from many standpoints, lease of which is profit.
People have not shown much interest in the green twin.
One guy did build and publish a bar-stock version of the green twin in Live Steam recently, and it was pretty decent.
What I really want to cast is a Frisco Standard single.
I have not done any IC work, and am itching to learn it.
And you can't get Frisco Standard single iron castings anywhere in the world, unless you make your own.