body panels

Hey guys just getting to the body work on my 88 K5. The only piece that I am still missing is the filler between the tailgate and the rear bumper. Does anyone know where I could get one?

I'm in the process of tearing down my 77 K5 and planning out the build, and am considering replacing the fenders, hood, and door shells. The parts currently on my truck aren't terrible; the fenders do have some rust and the doors and hood would need some work before paint. Just thinking that if...