nope not sears,or JC whitney
... but a hint,The company bearing the inventors name ceased being an entity recently after 100 years of being used as a trademark.
The 600 landau aka popemobile was built by mercedes,they did all their own work,no outside contractors were involved since before WW2. There was only one right hand drive landau built,I had the oppurtunity to look close at it a couple of months ago. A seriously BIG car,and it has always been privately owned unlike most of the others which were owned by governments and despots of various sorts.