I also don't understand the "selling for profit" part of this.
So if I bought a Mosin or SKS back in the day for $99, if I sell them today at the going rate, I am going to make a profit. That makes me a dealer???
The SCOTUS already agreed with the "common use" test back in the Stun Gun case. ANd for that one, there were far less stun guns in circulation than there are pistol braces. So, the thinking is since the same common use argument was used for the braces, an appeal to reverse the latest decision...
Do you have a 1st gen Extar? I have a 2nd gen that came with a smooth buffer tube. They provided a blade brace that was not attached for me to decide whether to use or not.