Some pics would help.. At first I was thinking Peltier...but Egg & Ketchup doesn't strike me as a name even the name-naysayers would utter.
So, if ADV does stand for aventurine (it might) some more recent marbles come to mind....Would MAD maybe stand for a Jabo run? Madia (Madya) not sure of the spelling. Are there multiple marbles in each bag, if so are we talking about 2, 20, 200?
Any guess is good, and better than too few...right Bob?