Certain conditions must be met for this to be legal for both you and me:

1.  Your tube needs to be engraved.

2.  There needs to be at least some attempt made by you to complete your build, which is why you chose the Form 1 path. This attempt could be something as simple as a 3/16" pilot hole drilled in the end cap that perhaps you drilled off center. At that point you might have determined that you didn't have the expertise and/or the proper equipment to accurately finish your build, so you decided to send it to an S.O.T. for a repair.

3.  I will need a copy of the first page of your approved Form 1.
Spectrum Tactical Solutions