I guess Mayura draw won't help you for going into MoI because it also only imports the AI8 style stuff and doesn't seem to have an SVG importer.

It does have an SVG exporter, so it works for going the other direction from MoI to Inkscape (Inkscape cannot load the AI8 style .ai files, it can only load the newer PDF based ones).

I'm not sure if there is a good way to go from Inkscape to an AI8 file, according to here it was actually removed from Inkscape back in Inkscape version v0.47 .

There does seem to be some discussion of an Inkscape plugin for AI8 export here:
http://www.inkscapeforum.com/viewtopic.php?f=22&t=1037


If you can get it into Windows MetaFile format (.wmf) out from Inkscape, then Creature House Expression 3 may work to import that and export AI v8 : http://download.microsoft.com/download/a/5/d/a5d625a5-2e3d-4e9c-8608-6de48d7b569f/CreatureHouseExpression3_3.exe

- Michael