WW2 ID found

I am trying to help this French man locate the family so he can send them the ID he found "Good evening to all,
Found a us id of a us soldier that landed in omaha then fought in moselle.
His name is Bartkowetch Joseph
Form 32261307
T42 43
C nm
He survived the war and returned to the usa.
Unfortunately he passed away in 2004 and had no immediate family (wife and children).
I was able to find the address of his nephew and niece but impossible for me to contact because of my bad English.
I tried to send email without success.
Does anyone have a contact in the USA to help me finalize my research?"