Contacts missing in OS X 10.8.5

[audax2]

I am running a mid 2011 iMac with OS X 10.8. The addresses have all disappeared from the Contacts application. This happened in three separate stages: (1) I opened the application, which originally had about 100 addresses in it and found that only 20 were left; (2) a few hours later I reopened the application and found that only six addresses were left, and finally (3) when I opened it the next day all were gone.

I have a SuperDuper back up, on an external HDD and the addresses are all missing from it as well. I also have of some of the addresses in an older Snow Leopard backup, but I would prefer to restore all the addresses which were originally on my current Contacts application.

I have looked at various solutions on other websites, but not found any which solve my problems.

I have two questions.

(1) What can I do to find and eliminate the cause of the gradual deletions of the addresses?
(2) Once that is done, where should I look to find (hopefully) the deleted addresses, so that I can restore them to the Contacts application?

 

[organicCPU]

1. Check the preferences in Contacts -> Accounts (do sync with google?, is it a local account?, etc.), check the system preferences -> iCloud and Mail, Contacts & Calendars, check if any other devices connected to your AppleID do have some weird settings.
2. Try to restore the file –/Library/Application Support/AddressBook/AddressBook-v?.abcddb or maybe the whole AddressBook folder for images, etc. I didn't try that, hope it will work... or better, if ever have exported an Address Book Archive just import it. That's the way Apple recommends backup and restore.
Edit: The files in ~/Library/Application Support/AddressBook/Metadata/ with suffix .abcdp can be opened in Contacts without any problems. The .abcdg files should be the groups. Maybe you find them in your backup and can restore them.