In the early days of this site, Cedge, a member then, built just such an engine, almost exactly the same as the one shown here, to my mind, a lot better. He showed a blow by blow warts and all build of each piece, all taken from just an old illustration.
I have tried to search it out but my concentration isn't as good as it used to be. Maybe someone else can find it.
If you don't try it, you will never know if you can do it!!