Due to an increase in passenger traffic during the summer holidays, the Fat Controller borrowed the Posh Coaches to help him. Unfortunately, the posh coaches were incredibly rude and insulted Thomas, Diesel, Annie and Clarabel.
The coaches remained idle in a siding until a friend of the Fat Controller, the owner of a museum, expressed interest in purchasing them. After Diesel warned the coaches about the museum, they decided it was in their best interest to be useful and helped Gordon with the express.
After much hard work the coaches were dirty, much to the confusion of the museum owner. The Fat Controller then explained the coaches weren't his to sell.
Due to the fact that they only appeared in a "read and colour" story, the posh coaches have no specific livery.