This is an oil tank for a BT, 6v, but I've never seen one like it before. Could it be a Police bike ??
I've looked in all of my books, can't find any thing that looks like it. Found a BT Flat Head that looks close,
but it's not the same.
" Harley Davidson oil tank, and battery bracket from the early years. Good shape, and very usable for almost any bike. Definately in need of a new paint job." Item number: 160187106587