It is not required that you supply a copy of your DL when sending a gun to a dealer for a transfer or for selling. Dealers have their own personal requirements that may want you to do this.
I am also amazed that so many dealers do not not what is required and what is not by ATF. Many dealers think that ATF requires a copy of the ffl from the shipping dealer. Thats just not true. The only requirement from ATF is the sending dealer must have a copy of the ffl.
I know one dealer that wants a copy with each gun you send him. I have sent him several guns and each time he wants a copy. I tried to tell him that only one is needed, but does not listen
Best
John Boyd