Out of the box, the Century Link 660 is a modem/router or gateway type of device that combines the separate functions of a modem and router in one package.
Since the 660 is already providing routing services, the Time Capsule should be configured to operate in Bridge Mode to eliminate IP address issues and NAT errors that would result when two devices are both configured to operate as routers on the same network.
Concentrate first on getting the Time Capsule operating correctly, then you can tackle the setup of the older Time Capsule and and AirPort Express.
Since the older Time Capsule and Express are hard wired, you would configure both of them the same way to "create a wireless network" using the same wireless network name, same wireless security settings and same password as the "main" Time Capsule network.....and.....make sure to configure both devices in Bridge Mode as well.
(The "extend a wireless network" setting would only be used if you were connecting the older Time Capsule and Express using wireless.....not Ethernet.....so it would not be used in your setup.)
Once you have things configured correctly, you will have what is known as a "roaming" network with all of the Apple devices creating one "big" network. Depending on their location, wireless devices will connect to the AirPort with the best signal in this type of setup.
If you want to have separate networks in each area, then configure the older Time Capsule and AirPort Express to use different wireless network names. The downside to doing it this way is that you must log in to each network separately when you move a wireless device closer to another wireless access point.
