You might try checking some bike shops and see if someone has the correct type of spanner or lockring tool for the bottom cup. I would suspect that ravages of time have corroded the topcup and the locknut togather making removal with one set of pliers impossible.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk