I know that you just happened to find that coin with the hole in the head -- but it could easily be replicated by anyone with a sharp instrument. Plus your coin is literally rotting away and -- should you care to hang onto it -- you will see it get worse and worse until it is unrecognizable.
As for what makes for a valuable new error coin? You could check
ebay for error coins and see what out there. Generally speaking, the more spectacular the error the more it's worth.
To learn about error coins, check out this site:
http://www.error-ref.com/ To learn about die varieties for cents, visit this site:
http://coppercoins.com/There are more site with more information but these will keep you busy for quite awhile.

Happy hunting -- it's addictive......
Edited by Buddy
10/07/2016 7:39 pm