Is my great-grandfather Polish or East German?

[Smitty]

So my mom's DNA results revealed that her grandfather was not who we thought. We've narrowed his identity down to one of two brothers who were from Hinterpommern. Their family's surnames are German or Germanized Slavic. I'm trying to figure out if they were more likely to be recently Germanized Poles (Kashubians or Slovincians or something) or just East German settlers in the area or a mix of the two.

I used Vahaduo and reduced the sources to appropriate ones and got these results at a distance of about 6:

53.8 North_German
24.8 East_Sicilian
17.2 Polish
4.2 East_German

She has 3% true Polish and 6% East German ancestry, so I figure this unknown grandfather must be responsible for roughly 14% Polish and 11% North_German. That extrapolates to a 56/44 Slavic/Germanic mix. Does that allow me to draw any conclusions about his ethnicity?

[Peterski]

I'm trying to figure out if they were more likely to be recently Germanized Poles ... Slovincians or something

Check:

https://anthrogenica.com/showthread.php?23595-New-Samples-from-Migration-Era-and-Early-Medieval-Moravia&p=776465&viewfull=1#post776465

[Rethel]

So my mom's DNA results revealed that her grandfather was not who we thought. We've narrowed his identity down to one of two brothers who were from Hinterpommern. Their family's surnames are German or Germanized Slavic. I'm trying to figure out if they were more likely to be recently Germanized Poles (Kashubians or Slovincians or something) or just East German settlers in the area or a mix of the two.

I used Vahaduo and reduced the sources to appropriate ones and got these results at a distance of about 6:

53.8 North_German
24.8 East_Sicilian
17.2 Polish
4.2 East_German

She has 3% true Polish and 6% East German ancestry, so I figure this unknown grandfather must be responsible for roughly 14% Polish and 11% North_German. That extrapolates to a 56/44 Slavic/Germanic mix. Does that allow me to draw any conclusions about his ethnicity?

Only the genealogical research will give you the answer. Maybe Y-hg would help something, BUT SURELY NOT AU. NEIN! NIE! NOPE!

[King Niko]

Polish

[Smitty]

Only the genealogical research will give you the answer. Maybe Y-hg would help something, BUT SURELY NOT AU. NEIN! NIE! NOPE!

I'm not too optimistic about that. I don't have any town names yet, and at any rate there doesn't seem to be a wealth of extant records in Hinterpommern. But we'll see.

[Rethel]

I'm not too optimistic about that. I don't have any town names yet, and at any rate there doesn't seem to be a wealth of extant records in Hinterpommern. But we'll see.

Why?
In Prussia since 1874 state recording was obligatory, and before this, parishes were the centers of register.
Some sources can be found in Internet, some in Archives in Germany or in Poland, it depeds what. In Poland
we have wonderful scanning program, but unfortunatly a land which is an intrest to you, is not a priority.
From some 39,600,000 scanned documents, West Pomerania has only 4,600. Maybe Germans did more.

But if this is maternal ascendant, there is no sense to bother too much.
If you find something for curiosity, fine; if not, also fine — even better.