NGC rates the 45 at $6.50/MS63, but it is worth what someone will pay, right? Really nice coins, both of them. You obviously have done your grandpa proud taking care of them. :)
The primary purpose of grading a coin is to determine what the coin's market value is based on how well the coin was originally struck, how well the coin metal itself has been preserved, and how much wear and damage the coin has suffered since it was minted, and where it fits on the 70-point scale.