Last post on this subject...

Thought I'd collate the responses into a final list for us all to keep and study for that next Quiz Night. Apologies if any are still contentious - the ones below fill the criteria I set myself when thinking of the subject.

(1) (United States of) America
(2) Belize
(3) Bermuda
(4) Bolivia
(5) Columbia
(6) Cook Islands
(7) Falkland Islands
(8) Israel
(9) Northern Marianas
(10) Pitcairn Islands
(11) (Rhodesia)
(12) Saint Christopher
(13) Saint Helena
(14) Saint Pierre
(15) Saint Vincent
(16) San Marino
(17) Solomon Islands
(18) The Philippines
(19) Tristan da Cunha (named for its Portuguese discoverer in 1506, Tristao da Cunha)

Thanks to all contributors

stales