One other small thing about having a bank account in the name of the Trust, and paying for the stamp with said account, you don't need to include a Schedule A with the submission. I have been told multiple times that the reason for the Schedule A (to the ATF) is to prove that the Trust is funded - that's all. If you send them a check from the Trust's bank account it accomplishes the same thing. I have never included a Schedule A with any submission and have never had a problem.
IANAL - YMMV..