Clayton 7.1 Part (2) Insulation

The furnace from hell, part 2.

Ok from my other thread I was having a problem with something irritating my nose and throat. Well I took apart the top panel. Wow, I found a lot of loose insulation. The foil backing that goes toward the steel fire box was loose and missing in spots. So I took more panel aparts and remove ALL the insulation from the outer jacket. Scraped down the rusty spots the insulation stuck to. Took the leaf blower and blew everything out of there. Then to the hosed down and washed everything down, leaf blower again. Everything is back together now without any insulation,

So what can I use to insulate the OUTSIDE of furnace jacket? They had fiberglass that was about 1" thick compressed with a foil backing. This unit is outside under a shelter. Thanks

I looked up a image of the insulation and it was rockwool not fiberglass but still not healthy to breathe

Stove is 30 years old