As Dave said the “Bean book” is a big help esp. because it has some pictures. In the “free down load” section here you will find the inventory sheet. As also mentioned joining this club has some great perks. There is a great amount of information out there among the members that is unbelievable. Many times a handed down set, not only is missing a few pieces it will also have misc. pieces added. I just found a rare 1914 Mysto part box in great shape in a 1950 set. The owner said it was complete but they did not know the 14 parts were not the same as the 1950’s part tin.
As a side note, I commend you caring to hand the set down. Who knows it might spark interest in engineering etc., like the sets did for many in years past including my son.