I believe you are right that the masks add a 1.2 boost to ogerpon's stab moves.
These are the all the damage rolls I found with the leavanny: 51, 49, 51, 54, 51, 47, 54, 49, 51, 53, 52, 46
I also got a crit which dealt 71 damage. All of these, including the crit line up with a miracle seed...