Vintage Polsilver blades

Hi !

I got these blades and searched for information about these, but found nothing. Does anyone know what year they could be from ? Has anyone tried these ?
It`s a full and sealed 10 pack of blades, probably never gonna try these, they seem too valuable.
Package says "Made in Poland" and on the other side "Wizamet".

I have some vintage Polsilvers but the packaging is different. I guess mine are a non-export package. Otherwise they look similar. I have used some and I like them very much, but once they're gone, they're gone.