It's probably circa 1920s.
Extensive googling only turned up stuff like the following (NSFW):
1. Art gallery websites like the San Francisco Art Exchange
are better than most image-dump galleries, because they actually list the titles of the works. Unfortunately, the image in question does not appear to be on offer here or elsewhere.
2. Vargas ID list
has a lot of information, but again, I don't see this image glossed anywhere.
The reason I want the title is because I'd like to obtain a high quality print or lithograph, but not knowing what to search for makes it extremely difficult (I'm no Vargas buff or collector). I tried the brute-force method of just browsing through art print sites and galleries, but I guess it's a rare image, so it didn't turn up.