That fixed cup will be hard to remove. 20 years and moisture and lots of thread area and very little wrench flat area adds up to a hard case.
On the other hand, they will all come out with the right persuasion, so do not give up on it.
jim
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Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
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SB forever