Related to the mouse issue from another thread, I have a number of these vents on the foundation of our house.
On two of them the screen has rusted through. I don't think I can remove and replace the whole vent assembly, since it's essentially cemented into place. I can't easily attach a new screen on the outside, unless I drill into the cement. Same thing for the inside.
One idea would be to attach a wood frame around it with bolts into the cement, than attach screen to that.
Gluing doesn't seem robust enough.