He’s from my hometown is still a bit of a legend up here entirely for his toughness. He was never world class but a tough fight for most. By all accounts he had Len Harvey in all kinds of trouble in his British title tilt up here but Casey held back thinking Harvey was feigning something which apparently he was noted for. He also gave Thil a good fight who praised his toughness afterwards. He certainly earned the handle “Cast Iron” Casey.
You are entirely correct he had Harvey in trouble. the story is that Harvey grinned at him and ,that made Casey hesitant about going in for the finisher.