Office Excel 2016 update not applying.
Cause was my previous renaming of the Excel application in the application folder. 

In the application folder I had previously added the suffice 2016 to the name of the Excel program to delineate it from the older version (kept in event of compatibility issues with old files) from the 2011 suite. 

The download process added the update application separately with its original name "Microsoft Excel.app"  Deleting the old version, adding the prefix 2016 (as is my preference) to the new Excel file. Open this, and all works with the right version. 

So as tidy up, deleting the old icon first from the doc, then copying Excel with its appended name afresh to the Dock, and now all works and opens as version 15.34.0