The Late Lamented Luggage has a few cameo spots.

I noticed The Luggage in Unseen Academicals, which was relatively recent. A very brief thing though. As you will recall, Unseen Academicals features football amongst other things. Somebody got the bright idea that The Luggage, with all them feets, might be useful on the football field. That lasted as long as it took for somebody to upend The Luggage, on the grass with all them feets in the air. Bye Bye Luggage.

And then there was The Last Hero, in which Rincewind plays a fairly prominent role, probably one of Rincewind's later appearances. The Luggage followed Rincewind onto the spaceship, and into the cabin, but that I believe was the extent of The Luggage's contribution.