Dear bernarda, is easy to think that the surname could be Dallera, Pinasco and Lagorio are right... only in Genova archive it are the Liste di leva pertaining the birthyears interesting for your ancestor.. they have no the index... from 1815 to 1860:
"Consiglio provinciale di leva, regg. 70 ca. (classi 1815-1860,
con docc. dal 1792). Non ordinato."
unfortunately in liguria, as in all north Italy the civil records starting abt 1871, and before only the church records; in some case it are the church records in Liguria archive( La Spezia province if I remember very well), the your search as all search it must be made with logic sense; so it is necessary before to descover almost the right province, and after to think what Common it is probable as birthplace.... I don't know what let you think that your ancestor came from Liguria, because the surnames could be of some other region of Italy; in any case if you sure as Liguria region probable birth region, it is necessary to find the province... otherwise it is impossible... personally I think that Genova area could be probable; Pinasco could be of Cogorno town and also Lagorio... as always in this search the women surnames( Pinasco and Lagorio) it are the key of search...
You can ask a search in the Liste di leva of Genova province; here the address and the email:
http://www.archivi.beniculturali.it/ASGE/asge.htm
maybe they can find the militar service card of your Luigi(Luis).. regards, suanj