Like everything else associated with Nazis, the skulls are bogus. They were made in the 1800s for sale to a credulous public. Nothing Mayan about them.
Of course, they are probably still being made. No doubt in China....
Now this I could believe.
Uh oh. If that’s true, its gonna take a loooong time to get them all in one place!
As you say the skulls are fakes, made with tools of more modern origins for suckers with money.