What is this?

[old_tv_nut]

If the mask is out of place, it is apparently leaning back, that is the upper part is farther away from the face (hence the smaller blobs of impurity). Unfortunately, due to geometry, if the mask moves back by some distance, the yoke and guns would have to move back about 10 or 20 times that distance to get the beam angles right for purity, and that is impossible. If the mask is totally loose, maybe you could confirm even by listening for movement after removing the tube from the chassis and rotating it face down. Sorry, but so far this all seems to indicate an unrecoverable accident.