The Family History Library has the civil records of Castelmauro on microfilm. These are the birth, death, and marriage records of the town and cover from 1809 to 1910.
You can locate the birth, marriage, and death records that you seek by renting the microfilms.
Go to www.familysearch.org
and look for the catalog. Place Castelmauro in the search engine and see what is availale. You can also find the closest library branch to your home.