Here is an old thread from Dagger, a member from Russia. It is a comprehensive look at the early Russian engines that appear to be the forerunner of our beloved little 2 strokers.
There is a lot of speculation as to the history of how the Chinese cloned the design and began marketing it into kit form and exporting them. I believe Duane, of 'Thatsdax, has some information about the earliest kits. I'll call him and have him chime in with what he knows.