WMCO Sterling Earrings

Marked Sterling WMCO ( Wheeler Manufacturing Co) on the backs of the earrings. I have seen these white stones in their earrings attributed to white MOP, I am unsure of what stone they are. However, the shine and the way the light hits them are amazing. Could use a good polishing. Unsure if earring back are originals, as they don’t appear to be Sterling. From the top of the ball to the bottom of the dangle is approx. 1 1/8”