A few days after the auction closed, this Stark ball was reported to the auctioneer as being a modern remake. After a few more phone calls and a bit of digging by another collector willing to assist in sleuthing this information, a photo was obtained of 4 remakes in 4 different colors.
The balls are solid gutta percha that has been colored to create three of the four colors. They were made from a genuine circa 1900 mold. An image of the four balls is included with this listing.
I post this now, so all will have this information for future reference.