As Scrooge saw what he thought was the face of his dead partner Jacob Marley appear on the knocker on night of Christmas Eve it sets as a reminder of the events the he went through and the pledge he made to change
The no-bell prize.
doorknocker
It was the face of Jacob Marley
One can buy bamboo doorknocker earrings from Macy's. The Macy's store has both retail stores across the nation and an online store where earrings can be purchased from.
Its Bells reference to Scrooges new love - Money
I've seen couples where one person wears a normal barbell and the other wears a doorknocker and they stick the barbell into the doorknocker just to get laughs. I've never heard of it being used for anything necessarily.
It was Belle
There are many such words; blockbuster, bookshelves, choirmaster, doorstopper and doorknocker are some.
Ebenezer
Belle
Fezzwigg
Scrooge came from London