It is not clear what this is made from, although the last picture from the National Archives suggests that it is probably not chalkware (given the shine).
Winton Products (Blackpool) has a bit of a history I’m afraid. In a 1963 court case, British American Glass accused Winton of copying a design, even though it was made of a different design. Read the court papers here
1950s vintage chalkware statues 