At that age, there’s a great chance that the patent filing on that generator is about to become public property.

Corporations have been working hard to make the common person forget that the only reason patents have ever been granted (officially) was to induce inventors to document their designs for future public use.

It’s a big part of why the stuff you can get cheap from China nowadays is often surprisingly good quality, as long as it’s an older, tried and true, technology.