I bought a pair of Blitz jerry cans (red w/screw top) at a garage sale recently. I usually check the insides before buying but I couldn't get the lid off (figured because the can was so hot from sitting in the sun) and since the other one looked good I just bought it. But after letting it cool in my garage, it still wont budge. I've tried a screwdriver and hammer against the points and gotten it to turn 1/4 at most. The can itself looks like its taken a couple hits, but I dont see any warping of the screw collar. Penetrating oil obviously cannot get past the rubber gasket, so any ideas how to open this thing?