Obviously there should be 2 input fields near to the button for the username and the password. It should look something like this:
[image: dh8I_ExtensionStoreLoginScreen.JPG]
If the steps suggested by TIG won't help, please post a screenshot about what you see instead of the above. Also please tell us the operating system and SU version.
Do you have any other pictures of it? Any larger images? Dimensions?
I'd probably use Curviloft or TIG's Extrusion Extension to create the shape. I'd set out the curves at normal size, make a component of it and then develop the surfaces on a scaled up copy.
You could actually get away with using Follow Me on it, too.