Structurally, no difference.
The Waggy has the 4-light headlamp set (which means the headlight buckets are different, the marker lights and grille may be different,) and the "wood panelling," as well as different taillights (red/white vice red/amber/white - the waggy turn signals are red.) Apart from that, you should be able to use pretty much anything off an Cherokee on your Waggy - they're both listed as "XJ" in OEMR parts catalogues, and the only differences I've seen relate to what I mentioned and to exterior trim. A Waggy is little more than a restyled Cherokee.
5-90