Got it, I think, from the cats. C & U Mommens, South Heighton, nr Newhaven Sussex 1951-
Studio type pottery and moulded animal models. HS joined, incised or painted mark on Mr CHN Mommens animal models made at South Heighton. 1951-
Ursula, his wife presumably, had a different mark (like a double D) and did tin glazed and other earthernware from 1935. She started to make stomewares in 1963.
The S on the bull is upside down.
Info. Geoffrey A Godden Enc. British Pottery and Porcelain Marks