I'm about 90% finished with the conversion of a 2T to a 4kW hub motor. I've been posting over on Modern Vespa and an electric vehicle forum. If you're interested in that thread, follow it here:
http://modernvespa.com/forum/topic171911
Mods: if it is bad form to cross-post to another forum, I apologize up front and will remove or re-post in full here.