Yeah, that sounds like the Palmetto ones. I find his ones with the beads work for slightly longer then the ones without beads. I use the ones with the short brass/bronze ring instead of the long wire tail. I find the ones with the long tails bend after a while when used with off the ground casting.
Never seen a BOS mould for sale so can not offer any advice. Not a fan of breathing in lead fumes so do not make my own sinkers.