wall behind recessed radiator
Our 1936 house has recessed cast iron radiators on the first floor. Since we moved in last year, I have noticed that they emit a musty smell (especially in warm, damp weather when moisture would presumably condense on cool surfaces) and tracked it to the wall behind the radiators. When I went to try to clean back there, I realized that someone had installed some kind of unfinished drywall behind the radiator, in front of the original wall. It's basically an absorbent material, so it's probably full of mold and gross stuff. It feels pretty soft when I poke it. It looks like a pretty modern material, probably installed in the last 15 or 20 years. I assume that they installed it in an attempt to make the heat more efficient because there's no insulation in the wall behind the radiators.
OK, so I would like to get rid of that smelly wallboard material. My two questions:
1. any tips on pulling out the recessed radiators? I don't think they've been removed in a long time.
2. If I remove the wallboard, what should I replace it with?