If the bearings are right under that cap and you still don't see notches or splines to use a FW remover on, you might actually have to tear down the FW to get at the inner body and hopefully have a tool to get a grip at it to screw it off (I wonder if there could be flats on the inner FW body)......that's unusual, but maybe some here that have worked on older Suntours might have encountered the FW already and can chime in.
Keep us posted on what else you find out....

Chombi