I am so glad you are getting him and will get him started on a good diet! When I have had rescue birds with problems with beaks, I have found scrambled eggs, vegetables, cooked rice, cooked navy beans, birdie bread made with cornmeal and oatmeal are all excellent choices to help them get the nutrition they need until the beaks can get trimmed into decent shape. Of course mine love cooked meals all the time and they do get breakfast cooked for them in the morning before I go to work. Lol, I take better care of them than I do my poor DH - he has to fix his own breakfast!
Good Luck and thank you for giving him a new home!
BTW, a name will come to you once you get him home and can see how he acts!