I have an old Raleigh I am working on, the stem is stuck inside the steerer tube and so far I have been unable to separate them. It is nothing special, but there is a certain amount of pride wrapped up in rescuing/salvaging this frame.

I have turned the frame upside down and let some naval jelly sit, hoping it would seep down between the stem and tube. I have used liquid wrench and I have used what muscle I have. I am still stuck. This is not a new or rare problem. I am sure people much smarter than I am have conquered this problem.

What do I do next?