They wer'nt made yesterday that's for sure. I'd say 1920s/30s. Monetary value not much. But historical value high. Children played innocently with those marbles when the world as we know it today was far,far different. That by itself makesthe marbles worth more than gold.
I found a large spot in the back field approximately 100 yards square of broken dishes, glass, ect. I did a little research and it appears to be the site of a church dating from at least 1904. The field has been used for agriculture since at least the 1970's. thought i might do a little metal detecting and see what else i find.
The blue one looks hand made,1870-1915's, the top orange one possibly alley,The green colored one think master,The others I cant see enough of the marbles, the clay marble is also hand made from china I think.
ksmith
ive found about 30 similar ones in my back yard too. its strange how scattered and far apart they all seem to be. but i havnt a clue on any i.d good luck