>Could someone please tell me what is the most straightforward way to get to the full HTML source of a web page once it is loaded into an instance of IE or a WebBrowser control? ...document.body.innerHTML and ...outerHTML don't include the header stuff between the outer HTML tags. I'm looking for a way to reference the entire text, as displayed by the View Source menu commands. Is there a simple way to get to this directly from the document object?

You are using the right techniques to get what you can relative to the HTML source. The only way to get the entire source that you are looking for is to load the URL over HTTP directly not using the web browser control.