Pri Megadim's Ksav al gabei Ksav
This came out to be a nice mezuza...except for the erasure of the yud and vov in v'hayu (l'totafos). The impression of the yud and second vov are still visible, even though there is no actual ink left. The Mishna Brura quotes a Pri Megadim who says that it is a חשש פסול אפילו בדיעבד when there remains a רושם דיו. 1. Is this the case that the Pri Megadim is referring to? 2. Do we pasken like this Pri Megadim?