I am quite sure my parents had an encyclopedia set, and it would have been much older than the one you grew up with. I wonder what became of it? Or perhaps I am remembering the set of books they had with various stories and activities. There was one called "Things to Make and Things to Do." I remember trying out some of those ideas on a rainy afternoon. Like making a lamp for my dolls using a pencil and a muffin cup paper. This may very well be the volume I have in mind.