I've been wondering about this myself, unfortunately I cannot get any information on it, other than Tomos forks, swing arm, wheels, and engine fit it. No information available on gas tank, seat, or length/source for rear shocks. Information on a gas tank that will bolt on to it is especially important. Obviously, it is a project, and would require some fabrication, but it isn't like you have access to a huge pile of gas tanks, and can sort through them until you find one that fits. My understanding is that it also does not come with a VIN, so it would have to be inspected and registered as a custom built bike. Peace. Jerry.