In a large skillet melt butter, and add celery and onion. Cook until mixture is translucent, but not brown. Set aside to cool slightly.
In a VERY large bowl break up the cornbread and the white bread. Then add broth to almost cover. Take a potato masher and blend the two breads and broth. Add the 6 eggs. Then add the poultry seasoning, salt and pepper. Be careful with the salt, because there is still some in the broth.
Pour dressing into a greased throw-away pan. (I use non-stick cooking spray.) Start at 475 degrees for 20 minutes, then reduce to 375 degrees for 45 minutes or so. About halfway through cooking give it a good stir. This dressing is pudding-like when it goes into the oven, but it cooks up into the fluffiest stuff when it comes out!