:::I'm very glad that  weighed in, because this one is out of my comfort zone. ) There was actually a debate that just deadlocked at Wikipedia:Templates for discussion/Log/2012 May 28#Template:Non-free architectural work that hinged on the question of how international copyright law applies to us. I found 's argument convincing that we would be unlikely to supply protection to something for which we would not protect our own citizens, and some of those look like utility objects to me, although I'll grant that they're hardly every-day objects. The completed models are an entirely different matter.  

 :::If you have remaining questions after slogging through the reading, here's what I'd recommend (because it's what I'd do): head over to WP:MCQ or to Commons:Commons:Village pump/Copyright, link up the images, explain the complication, and ask them. If none of the images of the completed models are retainable, we may be able to keep one or two under WP:NFC? Again, that's not my comfort zone. But it's what I'd look into. And I'm sure it goes without saying, that I'd do my best to make the poor uploader feel better, since he has obviously worked very hard on this article and will be understandably disappointed if we can't retain some of these images. /  

 :::Uncle G, if my recommendations sounds off base to you, please let me know. I'm comfortable with most text issues, but when images enter can start to feel a bit shaky. ) If it were text, my answer would be "WP:C says we can't take chances and if there is any doubt we need to rewrite. So I'll help rewrite, and all will be well." It's not that easy with non-text media.