At the November Flywheelers show, I sold one of the adjustables that was made by Wakefield to a guy who seemed knowledgeable about Indian motorcycle's. It was his contention that motOcycle was used up until early 1930 and then it was changed to motoRcycle.
We got into this discussion because the Wakefield I sold him was marked motOcycle.
I have not verified whether his information was correct or not, so use it with caution.
Mike