Here's another thought.
Not only were Warwick and Indian geographically close to each other, but they both went back to the pre-motorcycle bicycle 1890s era in some form or another.
Were there any earlier exchanges or mutually shared projects or job work between proto-Indian and Warwick in the bicycle era that has been missed or forgotten?
I'm at a disadvantage here because I know so little about Indian, early or otherwise. It's like a strange new continent far away that is enticing and alluring as I know that new discoveries await the first explorer who finds them! The hints and clues are all there...