The coin that struck your coin is in it's old age. Nickels because of the nickel in the planchet wear the dies faster. Thus the outside rim is showing wear next to the rim on LIBERTY and date. The WE TRUST is showing weakness probably from a struck through error (grease filled in that area) but is not enough to demand any premium. A spendable coin, but it shows me that your eye is noticing details. So when you do find a doubled die, it should leap out at you. Other will vouch that often we are looking too hard to find something that isn't there.