I recently reverted from Mavericks to Snow Leopard on my late2010 MBA. I managed to get the wipe and reload accomplished and it works great. Unfortunately I didn't realize I couldn't retrieve my contacts and keycchain passwords from Time Machine even though some of the back ups on that ext. disk are from the original OS when I got the computer which was (and is again) Snow Leopard.
My contacts are on my iPhone 3gs running 6.1.6 and on my iPad mini running 7.1.1. Of course SL won't work with iCloud and neither device will pair with my MBA over bluetooth. For some reason i was able to restore my music library from Time Machine. Is there another way to retrieve my data?