Help with iPhones and Ubuntu

[Scott Ehrlich]

Please advise on the right place for this question if this is the
wrong place for it -

I changed from an iPhone 4 (iOS 7.1.2) backed up via iCloud, to an
iPhone 5S (iOS 8.1.3) with data restored from my iCloud account.

I have learned that once an account (iTunes backup/restore or iCloud
backup/restore) becomes involved with a device with a newer iOS, it
prevents you from restoring to the older device.

I prefer to revert from my iPhone 5 back to my iPhone 4, but due to
Apple's restriction, this is not possible.   The iPhone 5 has newer
information, just recreating the phone book on it would not suffice.

Both phones are seen by my Ubuntu systems (Mac Mini reformatted with
14.04 and a Dell Vostro 1520 also with 14.04).

Is there any tool/method (non root/hack) that will at least let me
transfer the data from the 5 to the 4?

I also have a Mac, if that helps.

Thanks.

Scott