Mistakenly bought one Anco 31-21 and one 31-24 wiper blade. I want to know what vehicles they fit?

They fit multiple vehicles - go back to the store and look at the chart or check the manufacturer's site: ANCO Wiper Blades: Products (http://www.ancowipers.com/products.html#p_transform)

They fit practically any vehicle with a 21 and a 24" blade.