State law still says a dealer "must" do a background check, even after it says comply with 18 USC 922. I'll be curious how the DPS and attorney general instruct the dealers when this goes into effect. Hopefully you're right and I'm wrong.
The way I see it: Gus wants to sell a gun to John.
John has CCW
Both meet at FFL.
FFL logs gun into his bound book.
FFL makes note of John's CCW
John fills out 4473
FFL signs and puts in CCW information where needed (just like today when you buy a gun from dealer inventory).
John leaves with gun.
It seems cut and dry to me, just the way it is done in other states that deal with this.