I've read through your previous posts. There are 6 different rare sparrows. Each one has 4 separate upgrades available to it which gives you a total of 24 legendary sparrows you can make. You may want to check both pages and by very careful when inspecting the names of the different legendary sparrows as some of them are very similar to each other (one letter or number difference). If you're upgrading one with one of the items from Xur, the legendary version will be available as will the rare version.