Try to PM Co-Chairs Pat Carol or Greg Feeler and ask for Dunlop contact information.
https://forums.bmwmoa.org/member.php?10-GREGFEELER
https://forums.bmwmoa.org/member.php?1349-Pat-Carol
Here's the contact form for the Rally Chairs
https://rally.bmwmoa.org/contact/
If they can't help try this contact page.
https://www.dunlopmotorcycletires.com/contact/