Just an FYI, the first picture is _not_ from 1949. It's from the 80's. A result of the SALT talks whereby the US and USSR would start dismantling nuke-capable offensive weaponry.
The planes were towed into position and chopped up in-place to ensure their numbers and disposition.
Also considering there weren't that many 52s on the planet, much less the boneyard fleet, until the late 50s, it's a safe bet it wasn't '49.
I happened across an article this morning while doing some unrelated research. There were only a couple jet-powered XB-52 prototypes in 1949.