I recently stumbled onto a site called retronaut, which features thematic retro photo galleries.
Lots of interesting stuff there.
Here are some samples (click on the titles to get the whole enchilada) from two galleries I thought y'all might enjoy.
Cartoons Vs. Old masters
Alternate history by Matthew Buchholz (fullsize to read the caption, it makes the image)
his etsy shop in which you can see many more of his creations (he has a cute picture in his etsy profile).