Ric - The plant in Reno is a complete plant from the design to the manufacturing to the assembly of there slots, they might get some of the electronic parts from another company but the last I heard they still made and assembled all there own machines. I would dought very much they would allow some other company to assemble the machines due to the fact this could lead to somebody tampering with the machines and getting their hands on the electronic parts.
The Travel channel has had a couple of featured shows about the plant.
Their are a couple of people in the Reno area that could confirm this if they take the time to read the message board and respond with a post.
Walt