I've been thinking... before the movie everyone was ranting about how prime didn't look GeeWun enough... Just recently, I've notice some simularities between 2007 Prime and a couple of old toys.... The torso, specifially the chest, seems to borrow a LOT from Powermaster Prime... and the arms look like they have some influence from Super Fire Convoy
i guess this could have been done to make old fans happy.... like starscream looking like a chicken to please the poultry lovers