I just begun my search on this, but does anyone know what kind of floor boards or sheetmetal pan would be in the rear of an 1918 Touring. Since there wasn't a battery there wasn't any need for access boards.
My '17 has a wood floor boards. Can send you pictures and any measurements. Don't think the '18 is much different.
Our '18 has wooden floorboards in the rear, but they are not removable like the front ones. They are permanently installed.