One possible reason it hasn't been hit hard by the buzzards is that it is on its tummy... Had it been on its side, they could easier get in the gut... Also I think they see the bloated shape better if the carrion is on its side so the legs rise up when bloated...
Also I was wondering what role your weather played in this thing lasting so long... And your noting lack of rancid death odor lends to that a bit...
Brent