file1.txt
Name,SSN,File
"Doe, John",123456789,3447
"Flinstone, Fred",000000302,1234

file2.txt
Name,Salary,ZIP
"Flinstone, Fred",34500,90210
"Doe, John",50000,10003

Output:
"Doe, John",123456789,3447,50000,10003
"Flinstone, Fred",000000302,1234,34500,90210