Preheat oven to 350 degrees F (175 degrees C). Grease two 9x5 inch loaf pans. Stir together the flour, cinnamon, nutmeg, and salt in a bowl until blended. Set aside.
Whisk eggs, sugar, oil, butter, honey, and vanilla together in a large bowl. Stir in zucchini, walnuts, and coconut.
Add the flour mixture and stir until well combined. Divide the batter between the prepared loaf pans.
Bake until a toothpick inserted in the center comes out clean, about 1 hour. Cool completely. Store loaves overnight in plastic bags for best flavor.