Yes I have been using Search and Replace with Places which certainly does part of the work. I posed my original question partly because the Places Clean could be a useful tool to finish the job. Places Clean will find those entries without Countries etc that have snuck into the database through downloads etc but without being able to set my own Country formats I can't use the Standard Name suggested by Places Clean. That leads to cleanup requiring me to type the country name etc rather than just a single mouse click on the Standard Name.
But the biggest issue then with Places Clean is that once I have used Search and Replace to name Countries to my preferences, all those "non-standard" (by RM7 standards) country names are identified as incorrect by Places Clean ... and so the tool becomes pretty much useless :-)
This discussion has been going on for quite some time, see links below from 7 years ago.