Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
But while more or less of an Etruscan character continued to mark these regions, it was confined to isolated remnants and fragments of their earlier power; the Etruscan nation no longer reaped the benefit of such gains as were still acquired there by individuals in peaceful commerce or in maritime war. On the other hand it was probably from these half-free Etruscans that the germs proceeded of such civilization as we subsequently find among the Celts and Alpine peoples in general.(10)
10. Cf. I. XIV. Development of Alphabets in Italy
The very fact that the Celtic hordes in the plains of Lombardy, to use the language of the so-called Scylax, abandoned their warrior-life and took to permanent settlement, must in part be ascribed to this influence; the rudiments moreover of handicrafts and arts and the alphabet came to the Celts in Lombardy, and in fact to the Alpine peoples as far as the modern Styria, through the medium of the Etruscans.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/2-04-fall-etruscan-celts.asp?pg=31