wrote:
The fixed cup has flats, right? Try clamping those in a vise
and rotating the frame to get the fixed cup out. Then use
Sheldon's method with a bolt, nut and washers to get the
adjustable cup out.

[this is a repost via google groups, as it didn't seem to appear
earlier]

Alas, it's one of those horrid Shimano ones with the internal teeth
that looks like a cartridge BB but isn't, so there are no flats.
Besides, my LBS already failed to get the fixed cup out years ago -
winter commuting on salted streets does take its toll.

I've used Sheldon's method before (on another frame) and it does work
well, indeed.

I'll try the penetrating oil, punch, and mallet next. If that fails,
I'll grind some flats. The poor frame's served me well, and it's almost
retirement age.