Thats just it....its not the same kit, other than the lower hull, the rest of the kit is newly tooled, not just the old kit with added sprues for the tusk parts.

http://www.cybermodeler.com/hobby/kits/tam/kit_tam_35326.shtml#.UVNNxDdu387

http://www.armorama.com/modules.php?op=modload&name=Reviews&file=index&req=showcontent&id=8599

2 separate reviews of the kit say the same thing, as well I have the Tusk here along with the older Tamiya M1A2, and I can say for sure that the only thing the Tusk shares with the older M1 kits is the lower hull.

The Bradley kits were pretty much the same, from the M2 to the M2A2, most of it is new over the M2, other than the lower hull, and maybe the wheels. The M2A2 and M2A2 ODS, there is very little difference, just the ODS items added into the kit.