My Bolles pal, the artist Jared Joslin (check out his link on this page) sent me this photo by Paul Outerbridge dated 1937. He thought that Bolles used it as a reference and so did I until I noticed that the Bolles cover was published in 1935. But now I think that Outerbridge borrowed from Bolles. He wouldn't be the first as I've found plenty of other examples, done both by photographers and artists.
Here's another example form 1927 and I'm pretty sure that the Bolles image came first. The caption on the photo was taken right off the magazine cover.
Now the next two go the other direction. These were photos that Bolles used for inspiration. For me what is most interesting is the changes that Bolles made in the covers. I've seen photos used by pinup illustrators such as Elvgren where the fidelity between photo and painting so close that you can superimpose them. On the other hand Bolles used these photos as a starting point but it was rare that his depictions bordered on a copy.
The example below is something different. The photo is of a model posing in Bolles' studio. But again you can see that the photo was just a starting point of what ended up being a very different looking image. I have a number of photos of models that Bolles used and what is interesting is that you would never recognize any of them from the paintings.