[Zope] reading File Objects from Python Scripts and External Methods

This relates to finding a workaround to my previous problem. I can create File objects with content='text/xml' using essentially the same program I was trying to use to write ParsedXML. The next problem is how to read them, again from an External Method or Python script, as a string. The plan is to convert the XML back into the simple markup to allow for editing. Of course, I discovered that the XML renders to nothing when evaluated using a <dtml-var .. >. :-(