my guess is that it probably dates to the 40's. I base that on similar ones being in a bunch that my Dad kept from his childhood. Here's a pretty good link to help identify marbles by manufacturer along with other good info. Perhaps with enough time to sift through it you can positively ID it MARBLEALAN.COM
I've found a lot of marbles and know very little about them, but do know the bigger the better ! Put it down in the marble forum ,somebody there will be able to help. Congrats !!