Until someone makes an accurate, full-scale reproduction using whatever technique they are promoting, it's all wild-ass guessing.
And we're left with a mystery.
No that is not true. This is not wild assed guessing, that is the realm of those wingnuts you referred to. It's called process of elimination and scale. If the carving can be done on a small scale, how does that negate the large scale? Why is a full sized model necessary?