Fred,
I think you're right about Ryan, however, Villiers, Scott, Velocette and here is a 50cc 2 stroke that does not pollute:
http://www.motorcycle.com/mo/mcvespa/et2.html
I am assuming it also has pressure lubed bearings, there does not seem to be any other way to do it.
They are talking like this should have been in production for 3 years, anyone heard of it?
Ron