In the vicinity of where the data plate should be, there should/could be a clearly visible "TD" cast into the block. That would give an indication whether the engine is an older model or a newer "Thick Deck" block.
As to who made it etc. - no dice without a data plate. There are usually some casting numbers but I am not aware of anybody having decoded all of these to be able to suggest a manufacturer. Because the engines are made to the same spec and parts are wildly interchanged during the truck's life, it doesn't really matter.
As for the turbocharger - looking at it tells you which model turbocharger is bolted to your engine. I does NOT tell you which engine you have. There are plenty of late model multis out there that received a loud "whistler" turbo as an "upgrade" and at least as many that came with a C turbo "whistler" from the factory and had a "D" bolted on sometime in their career.