Hello, my dad has had this coin on his bookcase for about 25 years and has finally gotten his curiosity up to find out about its rarity and value of this type of error. Any information is greatly appreciated;
Welcome, but unfortunately it is not an error. The coin has suffered damage, coins like this are often called dryer coins because the damage is often the result of being caught in a clothes dryer for an extended period of time. It is also possible that the damage was done intentionally.
I.cutter is right. No real extra value.
I have a few like it and always called them "Hammered" or "Bounced" coins. Made by folks with nothing better to do than impact a coin on it's edge.