So, Need41speed - what thread is it in the hinge pin? Info the next flummoxed owner needs! A link to the video might help them out too.

I recently had a similar hinge-pin removal conundrum, when the hinge lever on my Eco3 broke. Found the answer (3.5mm) at this 8-year-old blog post about Dahon frame hinge replacement. Given that his Vitesse and my Eco3 both used that size, a reasonable guess is that it's Dahon standard procedure for pins only accessible from one end.

Incidentally anyone stumped for old hinge parts might try JVBike.com, here in Vancouver - where I finally found a replacement lever. Former Dahon dealer with a box of old hinge kits in the back room.