My favorite "lost film" story is when someone found a complete copy of 'The Passion of Joan of Arc' in a broom closet of a mental institution in Belgium(?). Check my country there, but you get the idea.
It's so wild that it *still* happens.

Of the youth beware of these,
For some of them might rudely squeeze
And bite your cheek, then songs or glees
We could not sing, oh! queen of cheese.

We'rt thou suspended from balloon,
You'd cast a shade even at noon,
Folks would think it is the moon
About to fall and crush them soon.