Reinstall OS El Capitan “item is temporarily unavailable
After Factory Reset I selected Reinstall O S x ElCapitan then unavailable for the umpteenth time....
Have you ever downloaded El Capitan using your Apple ID? If you haven't, you will get that message. If your computer is capable of using it, try Internet Recovery.
Try booting into Internet Recovery (command - option/alt - R on a restart). It is a slow process. This will install the newest OS that the computer is compatible with. Reformat the drive using Disk Utility/Erase Mac OS Extended (Journaled), then click the Option button and select GUID. Quit Disk Utility. Then install the OS.When the computer restarts, you can use Setup Assistant to restore your data from Time Machine.