Indian Vertical Factory Racer
I read about the book you are putting together and I wanted to contribute a photograph. I am pretty sure the bike is a factory race bike. My grandfather (Walt Brown) is on the right and I am pretty sure Jimmy Hill is on the left. They both worked in the experimental department at this time so I am guessing the setting is in front of the Indian factory.
I think the bike is unique in that the one half of the gas tank is used as an oil tank. I don’t think that is very common. The rear 741 hub stands out as well. I am guessing the exhaust is from a Warrior TT.
Wally Brown Jr.