Silly question...

Assuming that a trust agreement has a "Right to Add, Withdraw, Amend and Revoke Clause"...can the Grantor/Trustor sell or otherwise dispose of (NFA related) trust property if he/she deems it in the best interest of the trust and all applicable laws are followed? For example, can the Grantor sell or trade a machine gun from the trust in order to finance another trust purchase? If so, would a note be added to the applicable Schedule A that the trust was no longer in possession of Item X?

I know this is a dumb question but I can't find the answer anywhere else (Prince, GunTrust Lawyer, et al).