Good morning.
As you certainly know there are several places named "Rus" ---
en.wikipedia.org
....and in Warmia Masuria are two....
Rus, Oltzyn, Warmia Masuria in German is Reussen, Landkreis Allenstein, Ostpreussen
[Reussen, district Allenstein, East Prussia]
....for more details please see here
wiki.genealogy.net
Church records for Reussen can be found in the parish Allenstein, church district Allenstein, East Prussia
An overview of relevant and available church registers can be found here:
www.archion.de
As you certainly know access to the church registers is granted after you bought a Pass / Subscription
www.archion.de
A quick check of the name registers / Namensverzeichnisse for baptisms / Taufen from 1779-1920 has no entry for the family name "Fandrich" or similar
www.archion.de
An additional check of the name registers / Namensverzeichnisse for marriages / Trauungen from 1807 bis 1926 also has no entry for a marriage of a groom with the family name "Fandrich" (of course the marriage could have been elsewhere...)
www.archion.de
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[Although you ruled this place out, I'd like to mention it as well .... just in case....]
Rus, Ostroda, Warmia Masuria in German is Reussen, Landkreis Mohrungen, Ostpreussen
[Reussen, district Mohrungen, East Prussia]
...for more details please see here
wiki.genealogy.net
Church records for Reussen can be found in the parish Sonnenborn, church district Mohrungen, East Prussia
An overview of relevant and available church registers can be found here:
www.archion.de
Unfortunately not all records are indexed (in example there is no index available for baptisms / Taufen for the year 1850). So it is required to search / browse thru the historic church registers manually page by page.
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However, I quickly looked thru the baptism records in the parish of Sonnenborn / East Prussia (to which Reussen belongs) in the years from 1849 to 1851 and could neither find
-a boy child with the given name Timotheus
-nor a family name "Fandrich"
-nor a child's mother with the name Magdalena Fuchs
(the family name "Fuchs" is present in that time frame, however not in Reussen but in Sonnenborn / East Prussia instead, plus the given name of those women is never Magdalena. The family name "Fuchs" is also present in Venedien / East Prussia)
(Church records for Venedien / East Prussia are also online available at Archion
www.archion.de
....however, as you can see there's a gap in the avaible records between beginning of 1828 to end of 1882 - say, unfortunately no chance to check if the person you are looking for may have been baptized there.
Same record gap exists for the marriages / Trauungen.)
(a kind of similar family name "Fuss" is also present in that time frame, but although this family resided in Reussen, the mother's given name is not Magdalena and they didn't have a boy child with the given name "Timotheus")
Kind regards.