I just did a little search. It is a cover of the Saturday Evening Post and it is called "The Doctor and the Doll" from March 9th, 1929. The model who played the doctor was named Pop Fredericks. Pop was used by Rockwell a number of times as as a cellist, a tourist, a politician, Ben Franklin, Santa Claus and in this case he played a doctor. I'll do some searching but that is all I have for now.