Looking for My fathers Biologiacal Family adopted 1946

I am searching for my biological family. My father was Born Harry Roland Montgomery on January 16, 1946. His father was Harry R. Montgomery his Mother was Corrine Whited they were married in Monroe County Florida in 1945 to. Corrine had 2 other children also a son born in 1943 and a daughter in 1944. Corrine's mother and father were said to be Dorothy Wright and Hiram Cathey. My father was adopted shorlt after birth by Ervin and Ida Tanner because his mother was killed in a Accident in Coller County Florida the same year of his birth in 1946. My father is very dark complected and he is told that he is native american he was forced to drop out of school because his adopted parents tryed to place him in a white school due to there color but the school would not allow it because of my fathers complexion. If this sounds close to anyone please contact me. As you can see I have information. The problem is Dorothy Wright and Hiram Cathey were supposed to have been Corrine's Parents however I cannot find a record of her ever being alive before 1945. We were told she married a whited as was her name on the marriage cert. in florida but cannot find a record of her marrying a Whited. When My father and his sister were little everything was kept real quiet and was never talked about other than what was said which is what I typed here. Alot of things dont add up and I dont beleive that Dorothy and Hiram were Corrine's parents and I would like to find out where Corrine came from etc. Also My fathers side the Montgomery's we have never meet at all in our life. My father is aging I made him a promise in 1999 that we would figure this all out before he passed. Here it is 2008 and still hitting brick walls my father is getting older and is starting to have some health issues as well of course we dont know what his family history is so that is of no help. Thanks