From where?

The Cohen/Ansell family are Litvaks, Marshall is proud to declare.
In Lithuania there are two towns with similar names, that could be the Neustot your grand father mentioned.
(see Schoenburg and Schoenburg, Lithuanian Jewish Communities)
Marshall recalls Fannies stories about how common it was to move and trade over the border with Germany and therefore we conclude that Naishtut-Shaki (Naumiestis-Sakiai) is the village where Reuben was born. And that is within the Kovno district.

Kovno, Vilna, Suwalki, Marijampole are among the important places in litvak history, and so they are in the history of the Cohn/Ansells as well as that of the Soells - Marshall's "other family"
This is a border area - here we have the historically floating border lines between Russia, Lithuania, Poland and Germany.
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To try and clarify a little:
Schoenburg and Schoenburg, p. 198:
Naishtut-Shaki (Naumiestis-Sakiai) Shaki District
Also known as Naishtut-Schirwint and Naishtut-Kudirka ...