Seriously? That's completely ridiculous on multiple levels. I'd hate to use the word bully, but this is what it sounds like.

There is a legal term called an "orphaned work" for a copyrighted work that doesn't have a clear owner, or an owner who can't be contacted.

https://en.wikipedia.org/wiki/Orphan_work

Orphaned works are *not* in the public domain. They are still copyrighted, and if the owner of the work should ever resurface, they could technically still enforce their copyright rights at any time. So, anyone who uses an orphaned work is rolling the dice.

As Aurich mentioned, patents are completely different. Basically, they cover inventions or methods of doings things.

Copyright covers creations, such as art, music, film, writings, etc.

Anything that is created is automatically copyrighted. However, you can also register a copyright, which makes the rights a bit easier to enforce in court (especially at the federal level) should a dispute arise and be able to potentially collect damages from copyright infringement.

https://en.wikipedia.org/wiki/Copyright_registration

Since when patents and copyrights are mentioned, trademarks usually pop into the conversation as well, but those are something else entirely. Those help enforce the use of a company's name, logo, special product names, special & specific terminology, etc.

Since you brought up ramps; functional objects cannot be copyrighted, trademarked, or patented. However, the decals (which have artwork on them) are copyrighted. That's sometimes why you see parts created without the decals.

Not quite.

US Patents need to be renewed at 3 years, 7 years, and 11 years. The renewals cannot be pre-paid or pre-registered for the maximum protection period. Patents expire after 20 years.

The laws on copyright vary and have bunch of rules and exceptions. But in general, with works created after 1978, authors get life + 70 years. Or, in the case of a company's works, 95 years after the publication date. Prior to 1978, works did not receive automatic copyright, and instead needed to be registered to receive copyright protection.

20 years is the maximum. There are no extensions.

However, what patent holders tend to do is take the patent, add or alter something, then patent that "new" thing with the addition/alteration. Drug companies use that technique all the time.