Cursed scroll of uncursing curses the item before message is generated
Cursed scroll of uncursing always displays a message "The cursed Foo glows in a black light." no matter what BUC status it had before reading the scroll.
For example using a cursed scroll on a blessed amulet of life saving produces "The cursed amulet of life saving glows in a black light.".
Uncursed scroll of uncursing works properly and using one on a cursed amulet of life saving produces "The cursed amulet of life saving glows in a silvery light."