So if I understand correctly, the first can you bought was submitted as an individual. You then bought a second one and used a trust in the paperwork submission. Now you would like to have the first one added to your trust. The app is still pending on the first one or have you received the stamp for it? If you have not yet received the approval then you can contact the ATF and say you wish to cancel that application and resubmit using a trust. They will refund your $200 in a few weeks. They can be a little slow or they might surprise you. At least this will keep you from having to pay for a second stamp to move it to your trust. The downside to this is it will move you back to the end of the line on wait time. Only you can decide which is more important, time or money.