: If it's copyrighted, you can use the design but not the name.
: If it's patented, you can use the design for a personal project, but not a
: commercial one.
: If it's patented, but the patent expired, you can use it however you like
: (but still can't use a copyrighted name).

From what I understand. I agree. I have looked a little into copyrights but not patents. Since this is a hard object and not an idea, slogan,etc I think this falls under patents rights. But it is my understanding that there is nothing that stops you from building one for your personal use. If you start making and selling then you are violating the patent law. But to build it yourself, for yourself, not a problem.