Totally forgot to update!
My suitcase came back on the 11th of November, basically 3 weeks after I dropped it off. Almost everything fixed, and a note of how to purchase a new handle cover from Briggs & Riley as it isn't covered by the warranty.
My wife's suitcase (dropped off at the same time) took longer as they didn't have the right spares in, I seem to recall it took about another 2 weeks. They did email to say it'd be delayed, but not by how long, and the first she heard was the text from DPD with the delivery details.
Not as good as Alba Luggage in Baker Street used to be, but sufficient!