When you look at teh external hard drive how many iPhoto libraries do you see? If you depress the option key and launch iPhoto how many iPhoto libraries do you see in the select library window?
Note that Most users recommend tha tyou do not hae your iPhoto library on a wireless connection - it is pron to problems - it is much better to have it connected via a wired connection
Have you tried restoring your backup (change the name of the existing library so you do not overwrite it)
You can try a file recovery application like File Salvage - you can download a free trial and it will scan the disk for you and tell you with might be recoverable. Actual recovery will require that you purchase the app. There may be many files with the same or similar names. Always recover the largest file size.
There are other such apps. Search on Macupdate or the App Store