If that's the nearest repair shop to the yards, you could have anything at all which had been knocked out as defective. There's an excuse for a bogie brick wagon for you, for a start.
I've just been browsing Britain from Above - I can thoroughly endorse the comments above, but have a look especially at the Baker Perkins pictures which come up when you search for Peterborough. Zoom right in and just feast your eyes on those goods trains - strings of single bolsters, a boiler perched up on a bogie trolley wagon, a batch of pipes loaded in whatever was to hand..... weeks' worth of ideas for all these goods trains you can have now you've cleared all your carriages off into cassettes.