My dad was given a Colt .45 DA revolver by an elderly friend of his. The friend says he carried it as a border patrol officer in the 60's. It is blued with a black grip and a 4" barrel. I have been trying to find out what model it is but I am stumped. The only marking is the .45 long colt stamped on the barrel and the serial #. Thanks for any help. The gun is in Oregon but I am going to have my dad take a cell hone pic (if I can coach him through it).