The answer came with the photo of the tank's bottom — someone decided to channel the popular 90's ram air trend (like the Bimota pictured below) by, apparently, installing two tubes through the tank, presumably to increase airflow to the carburetors? I'm not sure if the caps are removable and if flexible tubes are supposed to be connected to them. Our seller doesn't mention this unique modification but describes the tank as "very nice" and is asking $150 OBO plus $20 shipping from Iowa.