http://www.ainm.ie/Bio.aspx?ID=1611 Tomás Tóibín. 1920-2002 = poet, translator and polyglot (employed as a clerk and then as a timire - travelling rep. for Irish language organisation, later as a teacher, a translator for Irish parliament and for the publishers an Gum) He was raised speaking Irish at home, but in a larger English speaking community in Cork. Learned some other languages as an adult. Studied Russian language with the one text he could find, an Orthodox bible. The page doesnt mention Trasna na dTonnta, but does mention that Tomás translated The Limerick Rake into Irish Gaelic.

for readers of Irish language, another article about Tomás Tóibín: http://www.irishtimes.com/culture/2.663/troscan-na-ndanta-1.1049424

I do think he is correctly attributed with the translation of Westering Home as Trasna na dTonnta.