Eas the UW exhaust option available as early as 1926? I have seen it on motors as early as the TR40 but that may be a motor that was sold in 1929 when it became available on the other models.
I recently acquired a 1926 P30 that has a muffler with the studs for the down tube of the underwater exhaust. I see no signs of a lower mounting point. I would guess that someone added it later on but am not certain.
Does anyone have a 1926 accessory book?