Old Time machine backups stored on GoFlex storage not visible

How to find older Time machine backups stored on my GoFlex storage drive?

Hello - I have been using GoFlex as my primary backup once my original Airport TC was full. Recently I upgraded to Yosemite and after successfully installing the new OS, restored my last good backup from GoFlex.

After a few days, I found out that all of the pictures in iPhoto, that were not modified in iPhoto, were not restored during backup! In other words, the "Original" folder inside the iPhoto Library package is empty. I am trying to create my daughter's HS year book page and don't have all the pictures and it is very frustrating.

Now if I go to my GoFlex backups all the previous backups before I upgraded to Yosemite are no longer there! The oldest backup seems to be very first backup done after Yosemite was installed. It looks like TM lost track of previous backups and showing backups only after the Yosemite upgrade. This is strange because, after Yosemite upgrade I was able to restore my whole user data from GoFlex.

Looking at the free space on GoFlex it seems all the old backups are still on it somewhere, but not visible to TM. How can I get those old backups, either through Terminal or through TM? Can someone help, please?

Thanks.

Mani