This is an old but interesting article from ARTNews that contends that Marcel Duchamp's famous "ready-made" art objects were actually crafted by hand, or at least reworked in considerable ways by Duchamp himself. The author, Rhonda Roland Shearer, came to this conclusion after an exhaustive search of early twentieth-century catalogs and antique stores failed to turn up any items identical to Duchamp's snow shovels and bottle racks:

Shearer came to many of her conclusions by trying to imagine if the objects Duchamp presented as manufactured items would actually function. She found that his snow shovel, titled In Advance of the Broken Arm, would break for lack of its patented triangular back supports, and that its square handle would hurt the user's hand. She concludes that Duchamp bought and altered it. She found that the birdcage in the "semi-readymade" Why Not Sneeze Rose Sélavy? at four and a half inches tall is too small for even the most diminutive parakeet. She contends that Duchamp cut the original cage in half.

This is the sort of hands-on, obsessive, obvious-in-retrospect idea that I can't help but admire. The article, which I'm blogging only because I stumbled across it just now, is undated, but it's evidently a few years old, because it was written before Shearer's husband, Stephen Jay Gould, passed away. I imagine that they must have been one of the great fun couples of recent years.