The latin text has little to do with the French text, and is therefore of no help to understand the obscure parts. Here is a possible transcription:
Cupidum imperii Caesare civitatissent
A Caesare regnum Galiae intellexissent
Caesar Caesare Caesar
Ubi ex captivis subsidio copiae consendissent
Cohortibus decem praesidio navibus essent
Caesar Caesare Caesar
Communi concilio ex continenti
Rem esse testimonio sesse mederi
In Galiae morari
Sed esse Galiae communi concilium
Omnibus hibernis Caesaris regnum
Filius et fratis filius
A Caesar Caesare Caesar.
A version in Latin was published on the same 45rpm. Several versions exist, which appeared in 1976, 1982 and 1984, with lyrics slightly differing. Parts of the text remain obscure, especially lines 4-6 in the third verse.