Just reach out to your GML and show them that you started your Jango long before the changes were made. When I found out about the changes in March, I told my GML and showed him my build thread here to prove the date I started and they allowed me to be grandfathered in whenever I finished. And I literally finished and got approved last week without any issues for my Arena not having a dent.
I also started building Jango in 2010 and scrapped/re-started the project multiple times since so I know exactly what you're going through. And yes, I'll eventually upgrade my helmet to a dented one as soon as I can snag one off Cruzer but don't let that stop you.