Jeff Wisnia wrote:
589 Keyhole cover. Don't remember where I saw them, but they hang
on a screw above a keyhole, hanging down by gravity. Push to one side
to insert key.

Yer dead on! I submitted that one. I picked it up from a trash heap
behind a hardware store (ironmongers?) in England about 30 years ago.

They were used to keep the Butler from seeing what he shouldn't see. G

Jeff

We still use them on outer doors to protect the lock from windblown
crud, and to keep the draught out!