Eboraci in Anglia, beati martyris Thomas Welbourne, qui…At 15:
In urbe Nam Định in Tunquino, Sanctorum Dominici Nguyễn Văn Hạnh (Diêu)…Where on earth are these places?
Someone with a classical education – even one who is not familiar with the names of the counties or TV stations can presumably be expected to know that Anglia is England, but will he know that Eboracum is York, even if, under that name, it was the scene of the proclamation of Constantine as Emperor? Italics in Ecclesiastical texts indicate the vernacular form of a word so Nam Định is clearly the form of the name in the railway timetables. One might guess that Tunquinum is Vietnam. In fact it is the northernmost part of that country, Tonkin. This was (…Wikipedia…) one of the historical divisions of Vietnam borrowed by the French for administrative purposes and used by the Church. Hence Annamia, Cocinchina and Tunquinum should all be translated as Vietnam.
At 4:
Gerundæ in Hispania Tarraconensi, sancti Felicis…This is nothing to do with the fabled part of speech familiar to students of Latin. It is the city of Girona in eastern Catalonia. Hispania Tarraconensi was the northernmost province of Spain covering the territory of Catalonia, Aragon and Navarre (more or less). Saints of the modern era are said to die in Hispania, not in the historical Roman province. So Blessed Enric Canadell martyred outside Girona on 17th August 1936 is listed at 11 for that date:
Apud oppido Castellfullit de la Roca prope Gerundam in Hispania, beati Henrici Canadell…I have not found a single source to translate Latin names into their conventional English forms. The Lexicon Nominum Locorum by Carlo Egger translates from the Vernacular into Latin. It seems to be restricted to Dioceses. Faced with a puzzling Latin name, one can always search Catholic-Hierarchy.org. Unless you are familiar with the meaning of Wagga Wagga you are unlikely to guess that some inspired Latinist gave it the name Corvopolis, City of Crows.
Otherwise the only two resources known to me are the RMBS/BSC Latin Place Names File and the Cathedral Libraries Catalogue : Names of printing towns. These are restricted to places where books were printed.