I ordered a whole barber box 100ct of Wilkinson blades. The box came sealed and the black tucks inside were all sealed too. The date on the carton is from 2017. Since this is my first time buying wilkinson blades I was wondering if this is how there suppose to look. I opened up 3 tucks and they all looked the same with brown spots that didnt wipe off. The glue would come off but the brown mark's didnt. I didnt use any of them. Could it be rust or is this just how they look?