Before I wander off to the mango and peach salsa, I leave you with a few quick pointers for telling 1870s and 1880 big bustles apart.
1870s gowns tend to be lighter in both color and weight of fabric. 1870s gowns are fuller in the skirt all around the body and tend to come in separate skirt and overskirt construction. 1870s sleeves often are just short of full-length and wide wrists finished with a lot of pleating. 1870s is more likely to have contrast sleeves
1880s more often darker and more substantial fabrics and colors, but not a hard ruke by any means. 1880s skirts are a more tubular shape with attached draperies rather than separate overskirt. 1880s bodices are longer waisted and more fitted over the hips. 1880s dresses have a higher day neckline with a stand collar.
These are general tendencies. There are exceptions everywhere. If you engrave this information in granite in your brain tissues, you are being way too rigid. Especially for a fiesta.
Now you are prepared. Go forth and hunt the massive, yet graceful, bustle.
1884 2-piece Brocade and Taffeta Afternoon Bustle Gown at http://www.antiquedress.com/
Early 1880s Green Faille Bustle Gown from www.pastperfectvintage.com
1880s Sage Green Taffeta & Cherry Red Velvet Gown from our archives
ca 1885 Wine Silk Taffeta and Brocade Dress from our archives
Mid 1880s Blue Silk & Gold and Blue Plush Gown from our archives
1888 - 1889 Black Silk Tea Gown from our archives