Just got an inexpensive but fairly well detailed cast copy, right down to thew missing teeth, which appears to be in copper alloy (better than the originals! (not painted, i tried to strip it - could be copper plated zinc however). The artists's initials below the skull are P(?)G.
There is a set in 3 "grades" (black, silver, gold), i believe out of the UK but quality is poor.
There is a set in 3 "grades" (black, silver, gold), i believe out of the UK but quality is poor.