Barbers and Poland in the 1920s

My great grandfather Alvin Barton Barton and his wife Lucy Lombardi Barber went to Poland in the 1920s to help rebuild the Polish railway system. "Vin" aka A.B. Barber was the principal, but my sense from family history is that Lucy wanted to go along and she brought the 4 children, Geoffrey (jeff), C. L. (ciel, or Joe, or my grandfather), Janet, and A. B. jr (Vinnie then, later Bart) quite enthusiastically. Today my father sent some letters written during their time then. What stands out for me is my great grandmother telling about how much her children were assaulted by german children during this period. All of them, ages 8-12, faced gangs of children who regularly punched/beat them up. None of them had encountered this is Washington, DC before. My great grandmother describes this as good for them but is clearly disturbed that her children must fight back to survive. She is proud that they do, though she writes that she is a "pacificist" and is not happy to discover a growing hatred of Germans. In case, anyone wants 'fair and balanced,' she's not too happy about the power of Polish Jews either.

As much as I feel like I lived through some interesting times, this adventure does fascinate me. It is well documented in the archives. My Zotero database indicates these sources
Register of the American Relief Administration. European Operations Records, 1919-1923 as well as this report:
Report of European technical advisers mission to Poland, 1919-1922
and several other sources.

I have to do some family diplomacy to get wider access to these letter, but in the meantime, I'm glad to know they exist.