I know that the registers of "pubblicazioni di matrimonio" (and their "allegati") were filled up by the Registrar but at the end of the year they were sent to the "tribunale" together with the second copy of all the other registers, and physically archived by the same "tribunale".
Nowadays a lot of "tribunali" had poured over their archives to the "Archivio di Stato" of their province but i'm not sure if all of them really did it.
I recently confirmed that my great-great-grandfather was born in Garzeno in 1836 and emigrated to America in 1863. In preparation for a visit to Garzeno this summer, I have been researching any relatives of my g-g-grandfather who might still live in Garzeno today.
I found that my g-g-g-grandparents also had a daughter, so my g-g-grandfather Giovanni Domenico Matteri had a sister, Maria Matteri. She married and had (at least) 5 children in Garzeno. One of her daughters, Domenica Robba, married Pietro Antonio Bordessa in 1885 and they had (at least) 7 Bordessa children, 3 of whom lived to be adults and married. Two of her surviving children had their own children: a daughter, Graziosa Bordessa, who married Giovanni Mazzuchi in 1924 had 4 Mazzuchi children; and a son, Pietro Donato Bordessa, who married Rosa Estarina Maffioli in 1925 and had 6 Bordessa children. Given their birth years, at last some of that Bordessa generation are probably still living -- I found one of them in the PagineBianche (white pages of the Garzeno telephone book).
So we might be somehow related! I am still researching down the lines to as current as possible, but would be happy to send you the chart I have put together so far. By the way, the inter-marriages, and reuse of family names, in the 1800's and early 1900's in that small village of Garzeno makes doing the research and piecing together the puzzle very challenging -- but fun!