[Ger-Poland-Volhynia] Birthplace or ancestor from Ehrgott Stach

[Gerald Stach]

Hello,
I am looking for my 4th grandfather Ehrgott Stach the place of birth or his
ancestors.
The brothers August and Ehrgott Stach emigrated in 1814 from Pawlow /
Petrikau after Besserabien Alt Elft.

In the book by Karl Stumpp is written "from Duchy Of Wurttemberg
about Pawlow / Petrikau after Besserabien".

Ehrgott Stach * Dec 1792, +19.01.1874 in Alt Elft / Protestant
married to Dorothea Gutsche
In the parish of the death record is as the birthplace "Poland".

August Stach * 1785 Duchy Of Wurttemberg, +25.12.1821 in Alt Elft /
Protestant
married to Mary Gutsche.

If Ehrgott Stach born in Poland or in the Duchy Of Wurttemberg?
How can I go here?

Thank you for your help.

Best regards
Gerald Stach