Will double check Richard but think it was "of pedigree unknown" where Drabble mentions staffies quite a bit. He talks of dog fighting as a popular underground sport dying out due to increased police interest, neighbours getting nosier and the dog men involved turning to whippet racing as it became popular again. I guess he us referring to 1950s or 1960s.
It was reading Drabble that got me interested in staffies and I pestered my mam and dad till I got one for my 13th birthday. Ge was a cracking dog and best present ever.