I don't see any pictures? The Delta 1700 series has 2 handles, one for temperature and one for on/off/volume.
As of the middle of 2006, the cartridges are different, but the trims should fit a new or old one, I think.
Are you sure you bought a genuine Delta 1700 trim, or is this something bagged up and dumped on botany bay or whatever they call thay site? And are you sure your valve is a Delta 1700? Some pictures would help clear this up.