Hi. I'm new to this so I need some help. My home was built in 1924. We have several areas where there are cracks in the walls. I have figured out how to address those, but there are 2 areas where the top layer of the plaster is lifting. Based on my research, I believe it is skim & paint. Does anyone have any idea how I should handle this. The internet is full of advice, but I wanted to get an answer here. Thanks!