He really needs to be on a better diet as seed only is not very healthy for an african grey, you should try giving him some fresh veggies, raw or cooked and see if he will eat them, he may not at first but keep trying for sometimes they will eventually try them and who knows he may even like them. You can look in our bird food room for threads that have lists of what they can have and not have. He could benefit from having some legumes, nuts, rices and pasta in his diet also and occasionally some fruit, they usually will eat the fruit but they should have more veggies in proportion to fruits.
The addition of pellets would greatly enhance his nutritional needs and you can try different brands to find one he will eat, if he will eat the Harrison's High Potency kind that would be great as it is one of the most recommended.
We might be able to tell about the beak if we could see a picture.