My Dad's Name was Jim Criscitello and he fought on Okinowa, 15th artillery regiment. What exactly did your Dad do during the war? Maybe if you can find that out, you could narrow your search a little.
I have found out a little bit about my Dad's time in WWII, but like many of these brave men...he did not talk about it much. I really wish now I would have pressed him to share his stories with me. He died over a decade ago. Good luck in your research.
Connie