I hope someone can help me. I need to repair many cracks in plaster walls & ceilings in a 70 yr old home that I just bought. I need to get it right the first time (I'm a 66 yr old women doing it by myself)and there seem to be so many products recommended in my research that at this point I am I am very confused. Also, I understand that latex will not bond to alkyd paint - how do I determine if that's what's there? Is there some preparation that will let it adhere? Thanks for your help.