I still think
#49 is your best concept, but it's just not quite right. I would like to see the G filled in, but still a color representation of the dozer filling in the letters - like a map of the layers of the earth. I would also like the bulldozer to look less like a cookie cutter, if that makes sense.
Kind of like this:
http://www.fs.fed.us/r3/resources/geology/images/earthstructureUSGS.gifBut not that many layers. Just the top layer as if it were just filled in.
I know you're working hard on this, and I want to give you the feedback to make this as good as possible.
Thanks.