Book Cover: Titus Groan by Mervyn Peake

I'm an avid collector of old, illustrated book covers and this is one of my favourites.  I love this illustration where we see Lady Groan's white cats swarming over a statue in the foreground, then in the distance - recognisable by the various physical attributes Peake attributed to them - we glimpse Fuschia, Flay, Nannie Slagg and baby Titus himself (in Nannie Slagg's arms). 

Sadly since I no longer have the book this cover was attached to I don't know the publication date or the name of the cover artist.