I thought they had the ones for the gas tank, but not the round "100" decals. Are you saying they don't have either? If their tank decals are the wrong type, do you have any pics of the type you need that you can post?
EDIT: never mind, I searched the gallery and found this pic of a 71 TMX and the decals you're looking for. The tank decals that Diablo sells are for a 70 TMX....