I have found a supplier in the US who can cut from a photo of your old key, including the dimple type we have for the doors. In addition he will supply you with the key number for the new key. He can also take apart a cylinder and code + produce key. Furthermore, some cylinders have the key no stamped on the rear of the cylinder or the tail / lever at the back of the cylinder. I found a number stamped on the tail of the glove locker cylinder so here's to hope.
(The dimple type never made it into common use here so there is not one single locksmith who can even copy a dimple type key
)
Oh, and the tank lid can be taken apart to yield its cylinder.