I have a vintage frame of Reynolds 531 tubing. I added a longer stem two years ago. Now I need to remove that to send the frame in for repair. The problem is that I can't get the expander to descend. I have loosened the bolt and hammered it, but it has not budged.

It is a smallish frame, the seat tube is 52cm c-c
Could this be bottomed out against the narrow butted part of the steerer tube? Are steerer tubes butted?

I have read dozens of posts and pages related to stuck stems, and I realize this may be bonded, but the steel expander should release in any case.

How to proceed?