replying to myself here, but this might help someone else.

figured out that if I could reproduce the url of the original module edit, I could get back to the module.

so made a new page, put in a module, and used that url and subtracted one from the module number (it was the very next module added in that instance of my DNN install), and it worked.

but the xml output / xsl process is not working right; my xsl handles parameters just fine until I try to output the result as a download, then the parameters seem to get ignored.