After 3 months in limbo it's back soaking and I'm going to try again to get the stem out.
I'm figuring the Browns play at 9:30 on Sunday and by 1 pm or so I should be plenty ready to attach the bike again.........
I've soaked it from top and bottom with Kroil, hit it with heat and nothing......other than frustration and getting really pissed.
Either I'm totally missing something / doing something wrong or this thing is super-seized.
Hope to update with good news......
Here's an x-ray of what you're up against. Striking it from the bottom, while assembled, was a mistake because that drives the wedge even tighter than it already is. The proper approach is to first reinstall the bolt through the stem until it threads into the wedge below...but not quite all the way. With 1/4 to 1/2 inch of the bolt projecting above the surface, give it a good firm whack. That ought to drive wedge down, away from the stem body proper. You'll know things are correct when the bolt rattles around loosely, with the wedge suspended inside, like a bell clapper. Only then can the stem, bolt, and wedge be withdrawn as an assembly. Have you achieved this state?
Once you have accomplished this, the heat and the slippery stuff can begin to do their work. There are several ways to proceed, but I have a favorite. I like to wrap the stem in a rag and then clamp it, rather than the frame, in my bench vise. It doesn't have to be unreasonably snug...just enough to hold it firmly in place and prevent turning. Over tightening isn't needed and just causes blemishes. You can then use a length of 2x4, or other non-marring lever, to gently twist the now inverted fork from side-to-side, breaking the rusty choke-hold. Be sure to keep the lever as close to the crown as possible, otherwise you risk bending the fork blades. You want your energy focused as close to the steerer tube as you can get it--isolate those two offending parts. The concept--using the image below--is to separate the olive from the green, while leaving everything else unaffected.
Besides the Kroil, there are two other substances you are going to need--patience and resolve. Be sure you have plenty of both.