I found this description of copyright law on the web
Copyright Basics*
What is a copyright?
A copyright is the legal protection given in the United States to original works of authorship, including books, paintings, photos, music, video, software, and so forth. Copyright protection attaches to a work the moment it is fixed in tangible form (on paper, on video, and so forth) and prevents others from exploiting the work without permission.
Copyright is a bundle of rights
A copyright actually is a bundle of rights that includes the exclusive right to distribute, sell, duplicate, publicly perform, and create derivative works from the work. The length of copyright protection for older works is often difficult to determine, but for newer works these exclusive rights last at least 70 years, depending upon whether the author is a person or a company. The fact that a work is old doesn't necessarily mean that the copyright on it has expired. Until the end of the term of protection, a copyright owner has the right to sell, transfer, assign, or license one or all of his exclusive rights to someone else.
Selling versus giving away an item
Copyright protection includes the exclusive right to distribute or sell the copyright work. This usually means that giving away a copy of a copyrighted work (for example a copy of a videocassette) is not permitted. Thus, selling a pencil for $5.00, and including for "free" an unauthorized videocassette copy would probably be an infringement.
Copyright registrations and markings
In the United States, it is no longer necessary to register a copyright to enjoy copyright protection, although you may have to register your copyright if you want to file a legal action concerning your copyright. It is also no longer necessary to place a © on the copyrighted work, but it is a good idea to do so. The absence of a © doesn't mean its okay to copy the work without permission.
The way I see it, if someone makes a ship not related to an already existing show or movie (but a new race) They own the copyright as soon as its created, weather it be created as a wriiten story, a 3D model or just a drawing. Convertimg a newly created races ship to mod format wouldn't give any rights to Taldren for that design as long as its unrealated to Trek or previous work. So the new race couldn't use nacels, because nacels is trek related. Thus if someone creates a Hritonicalix race and releases a Hritoniclax ship powered by Rutosen Enhanced Cruise Thrusters RECTS I don't believe anyone could modify that ship in any with out the creators permission.
Though the general practice is, most don't mind if you alter as long as credit is given that its a mod of the original.
btw I now own the copyrights to the Hritoniclax and Rutosen RECTS.
Always remember that half the world is full of dung and the other half is beautiful. Do you want to spend the rest of your life fixing whats wrong with the world, or would you rather just ignore it and enjoy the beauty. Because in order to fix anything you have to work with it and who wants to work with dung.
Remember to keep your stick on the ice!
I am a projection of yourself. I am an individual that is a different person to everyone I meet. Because eveyone who meets me views me with different moral backgrounds, beliefs and experiences. I am a walking contradiction, partly truth and partly fiction