I opened up the rear of my Kenmore 80 Series gas dryer and discovered the following aspects of deterioration:
Corrosion near the bottom of the heater box. See photos 1 and 2.
Crumbling of the foam around the edges of the two large holes in the lint assembly. See photos 3 - 6.
With respect to each of these:
How concerned should I be?
Should I do anything to correct the symptom?
Should I do anything to prevent this from happening?