German Beer stiens

Many years ago my grandfather gave me to old German beer steins, but he never said how old they were, where they are from and a possible value. I am 60 years old so I know that they a at least 50, and could be older I know they are authentic but he grew up in Stuttgart. And moved to New York before the Great depression. I Know as a kid that he made many trips there
If you cannot help, could you lead me in the right direction
Here are some pics of the steins. The numbers on the bottoms are 3574 and 3577. They have the letter GRM. It is a big G with the RM inside the G. They are 8 1/2 inches tall.