Illinois, three 1 oz. squares of unsweetended chocolate is equal to 1/4 cup cocoa powder + 3 TB. butter.
Sounds pretty close to Freda's recipe.
I'll try it substituting 1/4 cup cocoa and leave the butter at 1 stick. (I know Freda's recipe called for even amounts like that.) Will use 3 c. sugar, 1 can evaporated milk, dash salt, and tsp. vanilla. I'll let you know how it comes out. Thanks.