Oh my Rhonnie, first the good news then the bad news, I don't know what to say except I am sorry that Ceasar flew out the open door, thats the one thing you have to be careful of with a flighted bird.
You have done all you can to either find him or to entice him home, I hope it works or someone finds him and returns him to you, I know you must be devastated.
So Bill got you another bird, no it won't take Ceasar's place but it will provide some companionship and then when you get Ceasar back you will have some company for him.
I am glad that you at least have some good news about Bill, hang in there and I pray that Ceasar finds his way home or someone finds him and returns him to you.