Thank you for the reply Legion. I wanted to release it under a CC license, but I don't think I can put some restrictions when it comes to distribution of the work with it.
Thank you for the suggestion Millenniumfalsehood. I think I will use this, but without "all rights reserved" and "used without permision" because I have to include who owns Dune and the movie and they have long names.
CC lets you choose the kind of license to use in your works.
http://creativecommons.org/choose/
That's a very good guide, and you can be specific at some characteristics.
For example, if you don't allow a commercial distribution of your kit (others profiting from the sale of it) you can choose a kind of license.
The same if you allow or not derivative works (like repainting).
Since the spice harvester is not an original idea of yours, and it's based on another person's design, you could not make profit from this paper harvester (unless you've bought the rights to reproduce it from the movie company or Mr. Lynch, or whoever owns the rights to it).
As for the "Dune owned by..." legal details come to play.
An illustrative article on that can be found here:
http://news.deviantart.com/article/106729/
It is a good reading to be used as a guide in this kind of cases, even if it deals with fanart of movie characters, but the same issues can be applied to the harvester you are making.
At the end of that article there's a couple of useful and more detailed links about (c). It may look a bit messy at first, but is not once the small details are understood.
To summarize:
The harvester is (c) Universal Pictures / David Lynch /whoever owns it today)
The
paper model of the harvester is an intellectual creation you made, based on the original movie harvester.
Though you don't own the original design of the harvester, nothing prohibits that you make a "fanart"/"fanmodel" of it. You cannot claim copyright on it, and cannot profit from the sell of it (that would be illegal in most of the countries).
You can freely distribute your model, as long as you don't profit from it and the company allows it to be distributed. Most probably they will never sue you or will never request that you cease to share it.
Since you are not a licensee, and you haven't bought the rights from the (c) owners, you don't necessarily need to put "Dune is (c) 1983 by ... " or whatever. Legally licensed products do it because they are bound by law to put the notice. The (c) notice in some toys can be very long because of that.
But since your work is a derivative/fanart product, it's not the same. You are not obliged to do it. However, recognition of the source is an ethical value. And you already have shown in this thread your concern about it. Maybe instead of a long (c) notice, just a line stating
"This model was inspired by and based on the movie "Dune" (1984) by David Lynch-Universal Pictures" will be enough. It gives proper recognition.
Notice that the name of Frank Herbert is not even mentioned here because he didn't design the harvester. The movie was based on his novel, but the mechanical designs were made by other people.
I hope this is not too confusing.