There is actually other Toshibas with removable GPU module.
The Satellite M50 (I have one here dismantled) has a removable X600SE graphics module underneath the board, this is a PCI-E.
I discovered this, because this machine will not boot, and there is no display at all. I dismantled it, removed the video module, and now the machine boots, but of course I see nothing. I am currently considering to buy a new video module from some part suppliers, to repair it.
I can even take pictures of this module if no one believes me :-)
Ross..