Gary wrote:

Sorry so long to respond. Sounds to me like you either
need to paint it all or replace at least one section.
You'll never be able to sand that out for touchup.
Good luck getting a good match to the other sections
though.

I suggest you call first a few painters and see what
they say and get (free) estimates to restore. I don't
think it possible. That stain goes deep. I wouldn't
take that job as I know it won't come out perfect.

One more *very important* thing. If you opt to replace
any wood and have it finished to match the other sections,
be sure to tell the carpenter to leave all scraps of
the new wood.

Painter will use those as samples to experiment with
the color to make sure it matches the old.
Once it goes on the ceiling, too late to change.