Hi Jon,
regarding Grasdorf: there's a so-called Ortsfamilienbuch (local family heritage book) available online.
For details see here: genealogy.net - Online-OFBs
In case of further questions please contact Hermann Bruett - his contact information is provided on the website above.
Etelsen didn't have its own church any earlier than 1965, before this it was part of the parish of Daverden.
Microfilmed church books of Daverden are available at the Kirchenbuchamt Hannover.
For details see here: http://www.kirche-hannover.de/kirchenbuchamt/index.html
Be sure to make an appointment at this archive in case you may want to visit them.
You should also be aware that the entries within these church books are recorded in historic German script (Kurrent) and you will have the need to be able to read/decipher it mostly by yourself since there will hardly be staff members available to assist you.
Other than that you may find this website interesting regarding Daverden, Etelsen etc.
http://www.daverden.de/index.php?show=22 (following this link will take to you to a list of emigrants from this parish).
In case of further questions please contact Rolf Masemann - his contact information is provided on the website above.
Good luck,
Vera Nagel
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