Three things come to mind:
I once found two rolls of pennies in the attic of an old school. Milk money? There were several steel pennies among them. They started my 12 year old son on a coin collecting hobby.
I once found an old "Cracker Jack" doll in another attic. I gave it to the new homeowner, and she about cried. It seems she had lost her favorite doll at age 7, it was just like this one! Kismet! She loved her new house after that.
Just last month, I ran across some old mildewed books in a basement. My wife likes old books, so I gave them to her. One of them was 180 years old. Another one was only 80 years old, she gave to her sister. It was a primer on reading, and her sister is starting a new job as an elementary school teacher. Sister loved it.
Do you guy collect knob and tube parts? The tubes can be used for final honing of your knives. Haven't found any use for any for the other parts yet.
Earl
