Done, only needed about 6 mm of tightening.
Made a tool to hold inner nut. Box spanner 11mm cut down to 40mm length.
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Found it easy to hold inner nut & after releasing outer lock nut, to turn the cable “grip” that allows a spanner. Then release inner nut & let cable go back to it’s static position then Re engage tool on inner nut turn cable grip repeat as necessary.