The interior door handles / armrests on 1979-93 240 models with manual windows begin to fall apart at around 6 to 8 years of age. As the foam inside the part begins to collapse the outer skin soon fails and you end up with an armrest that looks like it was mauled by a Rotweiler and passengers are afraid to touch it!
There really is no effective way to repair them, so replacement is the solution. Easily replaced in about 10 minutes with a Phillips screwdriver. Door panel removal is not necessary.
NOTE: These armrests are for 200 Series Volvos with manual windows.