Let's take these one at a time and I'll see if I can help. Your Curl was definitely built with the 'wrong' rear brake. There was a cryptic comment on the Kickstarter page that shipment of ~half the bikes was delayed by shortage of a 'critical' component. I can't help but wonder if that was the unusual 'left-handed' brake caliper. I'd take this up with your dealer and/or Dahon.eu.