Hope this link works:
1940 Census Substitute - Ancestry.com
It uses various directories. I was very dubious when I saw it, but I found my rellies in 1936/7, 1938/9 and 1941/2, and it lists the name, occupation and address of the head of the family, has his wife's name in brackets, and then when the oldest son was old enough to have a job he is listed too although he was still living with his parents.
So, worth a try - you might be lucky!
1940 Census Substitute - Ancestry.com
It uses various directories. I was very dubious when I saw it, but I found my rellies in 1936/7, 1938/9 and 1941/2, and it lists the name, occupation and address of the head of the family, has his wife's name in brackets, and then when the oldest son was old enough to have a job he is listed too although he was still living with his parents.
So, worth a try - you might be lucky!