Looked like this one?http://www.oatey.com/apps/catalog/sh...ubctg=4&prodgr...

Yes, the part looks like that except for there being 11 threads along
the inch. I already called Oatey and they say theirs have 9 threads
per inch.

OK. I will take your word for it that the ceiling simply
*must* not be disturbed. If it is that vital to save the ceiling,
and the part is NLA, then you might be forced to have the male
threaded part made-to-order. Or built up out of 2 or 3 parts.

Do you know a company that can do this? The ceiling below is our
dining room and it has a swirly textured pattern on it that is
repeated everywhere through the house. We have previously been unable
to get this pattern properly matched (in a repair done to our
basement). If we cut the ceiling, I think we would need to rip down
the entire dining room ceiling (or else we'd end up paying a lot of
money for a cosmetically unsatisfactory repair). Even so, it could
not be repaired to match the adjacent rooms, we would have a different
pattern in that one room from the entire rest of the house. The water
damage to it does not look that bad and I think it can simply be
painted over. I hate to get into replacing the whole ceiling for lack
of a $30 part.