Don't know if you saw this thread, bossingit,
http://www.ducatisportingclub.com/xm...6958#pid152287 but I'm getting some kits together for these. As the screens have large-ish slotted holes, I'm planning on adding in a larger diameter plain washer to fit next to the screen, then the o-ring, then ordinary washer and nyloc nut.
Post here or U2U me if you're interested.