I've recently come across a program, and accompanying hobby, that-in theory-could be applied to making various fiberglass parts for a Locost, or an alternative way to make a mold for a part.
Enter: Pepakura(or Papercraft)
It's basically a way to make a 3D, hands-on paper model from a 3D model on your computer. Make a 3D model in a program like AutoCAD, etc... import into the Pepakura designer, and it turns it into a 2D template that you print out, cut out, fold, and glue together to make your 3D model.
What makes me think it could be a possible tool in the Locost world is what can be done after you have assembled your 3D model. A lot of pepakura hobbyists take it to the next level. They use Fiberglass or epoxy resins to reinforce their models, followed by fiberglassing-some(more financially endowed) of the pepakura community have even used Carbon Fiber to reinforce, and then they use Bondo on the outside to sand and smooth to their liking. There are some amazing pieces(mostly Iron Man helmets, or Star Wars helmets) that have been made this way.
Not sure what all people would use it to make as far as parts for their Locosts, but something like...cup holders... comes to mind.
This is a link to the pepakura designer software. It has a price of $38 USD, which isn't bad for what it does.
http://www.tamasoft.co.jp/pepakura-en/There are plenty of youtube videos of people who have documented their projects if you are interested in seeing what it's about. One I recommend is this for his attention to detail as well as instruction
https://www.youtube.com/playlist?list=P ... 96B86684A9