Cloud and my devices are syncing, iMac is syncing new but not old

While I can now add a new contact from any device and see it pretty quickly and automatically on any other device (including my iMac), there are some differences between my iMac address book and the cloud and I don't know how to resolve them. There are both contacts on the iMac that aren't in the cloud and vice versa.

As mentioned I could add a contact to my iMac today and it shows up on all other devices. Likewise if I add a contact on my iPad it makes it's way to my iMac. But how do I get the cloud and my iMac address book to identify and resolve these discrepancies between the iMac address book and the cloud? I noticed the discrepancy because my wife's in my iMac address book but not in the cloud. I then skimmed through the list and I am noting discrepancies going both ways.

If no one knows how to do that, how can I export my Apple address book so I can isolate the discrepancies in MS Access? The only export format I see appears to only allow you to open it again in the address book.