"WW I James is single and might not have known his DOB specifically however, by WW II he is married and probably had to get a copy of his birth registration/certificate for his marriage license"

Yes, I wouldn't have believed this was possible, but I think this exactly what happened. I have obtained a copy of his birth certificate and it was issued to him on 10/28/1919, which would have been after the war. Interesting indeed.

I have a death date on Owen of 2/25/1939 and have sent for a copy of the death record to see what else I can ascertain.

Turns out Ellen's maiden name is CONNORS, daughter of John and Bridget CONNORS (oh what unusual names...NOT). Ellen was born in 1873 in Scotland and she died on 9/8/1899 of some sort of lung disease at the age of 26. My grandfather James was an only child. There is a death record for an Ellen Duffy, age 26, on 9/6/1899 that I figure must be her. The next of kin listed is James Duffy (her son??) and a Margaret Duffy. Here is the new mystery--apparently there was a Margaret Lamb that was keeping my grandfather informed of Owen's happenings after James ran away from home. He never had direct contact with his father again. So now I am wondering if this "Margaret Lamb" is the "Margaret Duffy" listed on the death record.

Isn't this just fascinating? I am so hooked on this I am getting nothing else done. I can't wait to get the pictures my aunt is sending me!!

Thanks for your interest. I love all your hints.