Looks like he had the pieces re anodized. You can see the scratches under the anodizing. Servo plate and knuckles also look like anodized black. All screws look like stainless or titanium and no hint of Phillips heads anywhere. Brake pads look current and although hard to tell, suspension plates look anodized as well but b block looks stamped? Really hard to say...maybe more pics needed. Also you should tear down the diffs and see if there are 2 or 4 spider gears inside ....that should indicate if it's an rtr or not. Shock bodies look darker than rtr versions too.
If it did start as an rtr, he sure spent alot to upgrade it.