Martin,
Is it the pan gasket that leaks, or the cork gaskets over the front and rear main bearing caps? Have you hammered the pan flange "flat" and kept the pan bolt torque to a modest figure...don't want to mash the pan gasket out. I used to install the front and rear gaskets over the caps with aviation form-a-gasket, let it harden so if you smack them when installing the pan they won't move. Keep at it!!
Stuart.
