As reveled on his very own website:
Eye didn't know he had it in him!
UPDATE: This just in, amazingly, from the late Marje Proops...
Many may think it an old wives' tale but my long experience as an agony aunt tells me that a new partner, a new book published and a new mansion invariably leads to choosing the decoration of the new nursery. And there are so many railway themed children's TV programmes to choose from.
But with 'steam' so popular in the titles of Christian's books I think we can safely assume it will be Thomas the Tank Engine wall paper.