I bought this tube as NOS mullard from Holland. Putted it in v1 of a vintage marshall and played for a while. Turned the amp off and some time later i noticed only this specific tube was simply looking different, it was white instead of black, and upon checking i realized it was just broke near the base pins... I dont think something made an impact on it but i also never saw a tube fail like this. I have read there are some fake ones like this out there and i thought it would also be the case. What do you guys think by looking at the pictures?