Yes - I added the link an above edit. Looks like same one as you - Wally Wallington is the mans name. This vid is all I know of him. I ASSUME its true - ie stone not polystyrene - pretty lazy eh?
The following is a quote from the Skeptoid Podcast about it, which is also referenced, and can be found here:
http://skeptoid.com/episodes/4202
Sounds like a hell of a task you have set yourself with the carving. Good stuff. The podcast is well worth a read/listen, if you havent already.
Thanks for the link KotA, promise I'll look, but I'm extremely skeptical of anything other than people and hard work being responsible.