I've just picked one of these up for my lad.
Doing some research it seems they were built in China for Sachs and the quality seems to be alright if not quite to European standards. The motor is based on the Miranelli which has some potential as I understand. Looking into the tuning side of things I've found a Taiwanese company called Nakaru I think which do kits and the like and are available from Euro Scooter Parts.
Anyone used these parts as there's a good saving on them over the European parts. Obviously I'd want to save a bit with the scooter itself not worth huge amounts of money although I have kind of decided I want to use a Technigas exhaust system.
Cheers.