As of February 1, 2019, the ATF has issued a statement on their Webpage informing those who have the NFA affliction there has been an address change to where forms are to be mailed. The new forms, such as Form 1 or Form 4, etc have been updated if you download the new forms here https://www.atf.gov/resource-center/forms-library
So, if you are a dealer, an individual, or a trustee...make sure to use the correct address for those pesky forms. If you are submitting a Form 1 or a Form 4, use NFA Division, P.O. Box 5015, Portland, Oregon 97208-5015.
Here is the link to their website for their detailed information. https://www.atf.gov/resource-center/new-mailing-addresses-many-atf-registration-forms