30 year old duct board

I'm sick of this exposed fiber glass crap. It's coming up on 30 years old and is in pretty rough condition. How do I fix it without drywall repair? I know I want it encapsulated, but should I do sheet metal, mastic, or something else? I'd prefer galvanized sheet metal but I'm not sure I have good framing to screw into. Might just be a loose duct board box.

When I replace it, I don't want exposed fiberglass, I don't care how well it is "bonded".

Any thoughts or suggestions?

https://preview.redd.it/dymfirscng9h1.jpg?width=3060&format=pjpg&auto=webp&s=263e9b28b95f6bb0409636351fb517f7ffa1d1a5