I've seen it a handful of times in some of the small villages in that area. Twice among relatives of mine (surname was Szklarczyk).

I don't have any evidence to suggest that they were Sephardim or Yekkes.

More likely, these are the "official" Polish document names, and not their "lashon kodesh" (Hebrew) names, which would likely be different.

Also: if somebody is named "Moshe Abram" and another child is called "Moshe Herz" (just for example), those aren't considered to be the same name.