Norway Civil Registration
Not all Civil Registration records (folkregister) for 1875 are on Digitalarkivet.
For church records not on Digitalarkivet, or on microfilm; you will need to contact the respective Parish Minister. Be aware there is a 60 year privacy law in Norway. Do not ask for information later than that.
For information from 1900 forward, you will want to contact the office called "Folkregister" for the area in which your ancestor lived. The phone number is 011 47 2207. Be aware Norway is 8 hours earlier than the Mountain TIme Zone in the United States. Also, be prepared to prove you are a direct line decendant.