Hi Paul,
I've bought Pleione forrestii, Maculata, praecox, grandiflora and saxicola in Vietnam at a local market. However when asking questions, most of which were lost in translation, it could not be established where they were from originally. Asian people in general (my wife is Thai) think it's better to make something up than admit to not knowing and 'loosing face' as they call it.
The plants I have which were flasked from my original purchases, do tend to be smaller than those from China but then so were the parents. I also find they do better and don't suffer from sudden death but again it may be down to my original purchases. I have also come across what looked like forrestii, maculata and praecox in Laos but never bought any as it was to long before I would return to the UK.
Chen Yi did of course sell some listed as Var Vietnam but who knows with her what they were and where they came from. She probably just used normal forrestii when the other ran out. Apparently someone said she has given up and now lives in Canada. There must however have been some reason behind why she originally called the Forrestii var vietnam.
David