Re: Handing over AE projects....?

If your agreement was for a final clip, I would call the director and discuss it with him and remind him in a diplomatic way that the agreed services didn't include source files.

If this is a regular client that offers a possibility of future work, you might want to negotiate a higher, much higher, like 5-10-50 times the original price. It's your talent, vision, and experience that enables you to produce the kind of end product they want to use. Giving up the project files is giving them you secret sauce.