This photo shows a tank from a General Moped. I believe its the same tank that Deringer Cycles for their bikes. There is an outfit called Handy Bikes that has this tank available as well as a slightly different tank that was for their 5 Star step thru mopeds. The tanks are only $50.00 but you will have to source your own gas cap and petcock. Handy Bikes USA - The largest distributor or vintage moped parts in the USA!
If you want to see additional photos of the two tanks go to the photo galleries at mopedarmy.com Moped Army - Swarm and Destroy
click on General The step thru tank can also be seen under the Clinton and Julie galleries