Thanks w8ye. Now the case is stripped, it might require a different tool. I managed to press the shaft out of the flywheel end bearing, but only after I had cut away much of the surplus alloy case. My puller then could grip the remaining flange and not the gasket face. Both bearings are the same size, 17x40, so that makes things easy. Also, the seal is 17x23, which might have to be genuine. Unless I machine the bore out to take a larger OD.
I'll see if I can post some pics. Not sure how to use this system yet.