I'll be glad to help if I can.I have four Arthur Coldirons in the database and five with middle names of Arthur; i.e. (first name) Arthur Coldiron.
There is one Arthur Coldiron who looks to be a possibility for your Dad.Arthur Brown Coldiron was born 17 Mar 1918 in Breathitt Co., KY.He died in Dec 1968.(These dates are from the Soc Sec Death Index.)The SSDI indicates his last residence was in Hamilton, Butler Co., OH.
I do not have a marriage or children for this Arthur.I also searched for a Marc Coldiron, and while I have one, he was born in 1993 and his father is Craig William Coldiron.
Tell me anything more you know about your Dad.If it isn't this Arthur Brown Coldiron, maybe we can figure it out.