Greetings to all..New member here. I am trying to identify a gas tank . It is a large one piece,about 4-5 gallons with a raised rib down the center of the top. The fill hole is large 3″ at the top right.The mounting brackets are lower front and rear bottom. One bracket is a hole and the other side is shaped like a hook.Same on the back but reversed sides for the hole and hook.The kneepad brackets are bolted on with two bolts well forward and the rubbers are teardrop shaped a little over 6″ long. The Zundapp crest is on the rubbers. The original color appears to be a pale green similar to some Sunbeams.Two petcock holes one on each side. I keep searching the web pictures but have not found this tank. Can anyone help?? Thanks Mike.