Many thanks for your answer.
In an elevated Command prmpt I can run:
net stop spooler
With the response:
The Print Spooler service is stopping.
The Print Spooler service was stopped successfully.
However the printer persists in "Printers & scanners" with "Driver is unavilable".
I can restart the spooler service and the the printer persists in "Printers & scanners" with "Driver is unavilable".
After some further research:
If I wait a minute or so
Then I switch/connect the printer I get the same "progress bar" as if the driver was still available and the printer is being installed, except it pauses and gets 'stuck' at around 10% progress.
If I disconnect the printer, I lose the "Driver is unavalable tag".
I can wait as long as I want. If I touch the elevated Command Prompt the printer disappears it disappears from "Printers & scanners". What appears to be a coincidence is remarkably reliable but starangely connected behaviour.
After further research, using "remove-printerdriver" I get "remove-printerdriver : The specified driver is in use by one or more printers." and the only way forward is to manually remove the printer from "Printers & scanners".
This removal of printers still appears very buggy. Why there is a GUI means to remove printer but no command line method beats me!