[pat in Santa Cruz]

a missing fiber seal is not uncommon. When you use the puller, are you sure the E brake is released? The puller needs to be tightened quite tight and holding the drum requires engaging the E brake. Then the drum needs to be released from the brake. Then strike the end of the puller squarely with a heavy hammer. I f its still stuck, try some penetrating oil down the key slot, and try it again with a touch more torque on the puller screw. Worst cases can often be remedied by installing the axle nut loosely against the hub to hold it on but allow it to move, re installing the wheel and driving the car around the block, then try pulling the drum again.