Are you trying to transfer ringtones TO the Revere, or FROM the Revere to another phone?
Try Zedge.com - you can choose from their free selection, purchase, or make your own. Once you register your phone, the tones are formatted to work properly. I've had no issues with the service.
You didn't mention custom audio files, And your right, The Revere 3 is a basic phone with not many options. I gave up rying it get a special ringtone for it.