Ikuo Hirayama A4 Clear File

This is an A4 clear file from the Ikuo Hirayama Museum of Art.

It has been stored for a long time.
I have listed it as near unused but it has not been used.

However, as shown in the 4th photo, there is a slight stain?
I tried to remove it but it wouldn't come off.
Both the plastic sleeve and the paper bag have tears.

Thank you for looking.