First time homeowner, house built in 1963, renovated in 1984. Trying to DIY what we can. Tore out the paneling above the cabinets today (believed to be original). Found this above the existing wall oven and the area to the left where I believe a countertop stove and hood used to be. Photo with brown area is over the former cooktop. The cracked area is hard. Black corner area with green splotches is over the oven cabinet. I think the panels are fire rated gyprock, hence the abrupt stop to the left of the brown area. Looks like they were partially painted over white. Cabinets and ceiling show no signs of damage. This is the only room in the house with a textured ceiling, so it may have been redone. Cabinets may have been relocated, but I believe these particular ones were not.

My concerns/questions -

What caused the brown stain? Heat, water, mold?

What caused the green splotches? Deterioration, heat, steam, mold, alien invasion?

We were ‘planning’ to take out the wall oven cabinet and tile behind it and above all the cabinets. What the heck do I do now?

(please overlook the spiderwebs!)