I picked these up a long time back and have never been able to identify them. The bell stamped into them is interesting. I do not know if it is a cancelation or ID stamp. (They are NOT Sands)

Celulose Nitrate dice, Red, Sand finish, Concave Spots and no serial numbers. The only markings are an "S" monogram on the 6 side and a small Bell? stamped into a corner of the 1 side. Starting to crystalize at the corners. These are
the oldest dice in my colection.