I've read their memoirs and autobiographies of others in the profession at the time, ummm. Sid James promised young actresses roles if they were nice to him, Hawtrey couldn't be trusted around young actors and stage hands, Williams used to travel on buses and trains to touch up boys/young men and Howerd was much the same.
I forgot Wilfred Brambell - horrible little man. He abused two boys aged 12 and 13 at the back of a theatre. Harry Corbett found it difficult working with him and loathed him.