For CMSimple_XH < 1.6x there was created the content.htm and separate pagedata.php. It means that if you'd merge all pages into one content.htm file (the pages are separated only by their headings H1...H3), the pagedata.php should be created automatically.
There'd be necessary to save used files (images etc.) into relevant subdirectories of /userfiles and adjust paths in content.htm (this can be easily done in exterenal editor by "replace" function. Conversion of such webpage to e.g. v1.6.10 is then absolute simple using exchange_xh plugin. The same is then with conversion from v1.6.10 to v1.7.2.
Not tested, but I think this shall work.