Put Backup on Old iPhone Is it possible, using iTunes, to put a backup of a currently active iPhone onto an older iPhone that has no service?

Basically I want to keep all the text conversations on a separate older device.

It's a backup of an iPhone 6 and I want that backup placed on an iPhone 4S.

Thanks!
Alternatively there are apps that let you download texts off, such as PhoneView by ecamm but I heard they stopped working in one of the most recent updates, so I would check the demo first.