Congrats! I just won the same battle last weekend!

I went a different route though. Chopped the top of the stem off to remove it from the fork, then flipped it upside down, placing the fork crown between two 2x10s propped up on my garage stairs. I put a long fat bolt into steer tube and beat it with a mallet til it came loose.

I had tried soaking in ammonia first, then liquid wrench so maybe that helped slightly.

I have another frame with a stuck stem, but the fork is much nicer (fully chromed) so I might just pay the $40 to have a local frame builder drill it out.