I was told if the old tub of 777 or pyrodex didn’t have the new stamp on then it’s legal to own without a bp license as it comes under the old legislation. Of course technically you could keep topping the old tub up with fresh powder if you could source the new gear lol .
I have a bp license with the new un coding on it but I feel it’s a silly law same as the brococks ….. which I have them also lol