Thanks for the compliment. I have been "into genealogy" for about 28 years and have lived in Lucas County almost twice as long.
I don't understand your comment, "If four out of five family members have changed their names for the 1940 census...". The only 1940 census I cited was in 1940 when the father David, and the mother Emily, their son Walter and his wife "Kathryn" lived together.
I can substantiate the various names because they were used in various Toledo city directories. In the 1916 directory, David Cooper was the head of household and a plumber living at 856 South Avenue. Also living at that address was Malcolm L., a repairer and Raymond B. a clerk. This is the address Raymond gave as his usual address on his WWI draft card.
In the 1917 directory, Frank D. Cooper and Wesley W. Cooper lived at 856 South. Wesley/Walter was a soldier but apparently gave that as his home address. Malcolm/Leroy is not listed but Mrs. Lucille Cooper, Raymond's ex is listed, living across town on Locust Street. Another example of switching names was Lucille who also used Cecelia.
In the 1925 directory, Frank D. and Emily Cooper lived at 1836-1/2 Broadway Street as did Wayne D. and Alice Cooper. This is about the time spouses were listed inToledo's directories unless, previousely, they were the head of household.
David Wayne Cooper's wife was always Alice and Walter Wesley's wife's name being spelled Kathryn was only how the census taker thought it was spelled; a fairly common error.
What info do you need to confirm you are searching the CORRECT David W. Cooper?