evidence docs for the US Citizen Grandparent's physical presence in the US

[USC2B]

Dear all,

I filled Form N-600K for my children and USCIS now ask evidence for the US Citizen Grandparent (my father) ,to proof the physical presence in the US.
My father lost (stolen) all of his US docs and papers 30 years ago, while he was returning from US to Europe (relocated permanently) .

So, I am searching now for docs and papers where initial issued 40+ years ago.
But I don’t know where I should address to … the factory where my father worked have closed.
I wonder if Social Security Administration could issue some reports back from 1970-80.

Any ideas … please.

[Paulthesheik]

Medical records from hospitals he attended, church records, Social Security records etc.

[USC2B]

Dear Paulthesheik,

Thank you for your reply. Unfortunately none of his US docs are now available (his briefcase where all this docs where stored, was stolen).
Anyway now I wonder if I could contact the Social Security Admin., and ask them to issue some reports ...