333V: Limited series of choose your own ending books

I am looking for (what I recall as a grade school kid in the early 90’s) a book series where you could choose your own ending. Similar to the popular “Choose Your Own Adventure” and “Which Way” series of books. I recall there being approximately 5-7 books with purple hardback covers. For some reason, I feel like I remember my school librarian telling me, after I read all the books and wanted more, that the authors didn’t make any more of the books and that there was only 1 volume.
I know this is a long shot! But I thought I’d try! Thanks so much!

333T: Boy Uses Light to De-Age Dog and Sister

This is a middle grade book probably published before 2008. It's about a boy who likes science and has an old dog and a teenage sister. The family goes to visit their grandfather, who's dying, and while there the boy discovers a light or something in the attic/grandpa's office. The boy then uses the light to de-age his dog back into a puppy and his angsty sister back into a pre-teen. He then tries to convince the grandfather to de-age himself to be healthy again, but the grandfather tells him not to. I remember the scene where the sister got de-aged because she was really different and kind of confused, since she had drifted away from the friends she had at that age and was suddenly signing up for high school classes. She called up some old friends and kind of made up with them, I think. I also think the boy had a microscope and a fort in his bedroom that he hid the light in while trying to figure out how it worked. I can't remember the title of this book, who wrote it, or what it looks like. Please help!

333J: Victorian Mansion Cross Sections

I’m looking for a children’s book I had back around 15-20 years ago. It was a large picture book of a Victorian mansion (or castle?). Each page was another cross-section of a wing of the mansion, and a brief description and clue of something specific to search for on that page before turning to the next. I remember one page involving a dance/ball, and another involving a pillow fight, and one involving a garden/outdoors. Each cross-section depicted multiple floors, and the top ones typically belonged to the wealthy family while the lower ones depicted the staff/maids/bulter’s quarters, etc. I believe the protagonist is a young female child, and I vaguely remember there being a pelican involved — not sure if that was a character or part of the title; perhaps a mascot who guides the girl through the book. The pictures were very artistic and detailed, somewhat sophisticated and very amusing, so likely a book for children over 8 years old.

332Y: The Figure In The Shadows (Solved!)

So here’s what I have:  I have very few details about this book. Read in late 1970’s-1980 (no later than 1980, but believe to be earlier).  Book (paperback) was a gift so I think it could be earlier than 1970s.  Geared toward 10-12 year olds.  Category: suspense, supernatural or mystery.

In the beginning of the book a boy (think it’s a boy, could be girl) is walking down the street when a newspaper or flyer wraps around his leg.  He looks at it and reads the word veni in Latin (I come or I am coming) and smells wet ashes.  Later in the book the figure/ghost is beckoning him to jump in a well (?) or off a cliff – he’s saved by someone, but that’s all I remember.  Hope you can help.

Edit: The author of this post found the title of the book before I got around to posting their Stumper: The Figure in the Shadows!

332A: Children Turn Into Insects

I am looking for a book that was read to my second or third grade class by a substitute teacher, and I believe this was around 1963 or 1964. Our regular teacher was ill and replaced by a young substitute, who craftily kept our attention by beginning each class reading one chapter of a book. She hooked us on her very first day, and we came to school each day craving another chapter like crack addicts needing a fix.
The story was essentially Franz Kafka’s ‘Metamorphosis’ for children. Here’s what I remember of the story, and time may have dimmed the details a bit:
1. Three children are spending the summer in the country.
2. They are largely unattached and indifferent to the surroundings and ambivalent about their summer vacation.
3. Somehow, all three are transformed into insects: the older sister becomes a caterpillar, the youngest, from whose eyes we see the story, becomes an ant, and an older brother, I think becomes something else.
4. They encounter daring and frightening adventures, and at the end of the book, they are faced with the possibility of returning back into humans, but the sister, who by this time, has transformed into a butterfly, opts to remain an insect.
This is all I can remember, but what struct me the most about the story was an overarching feeling of melancholy versus a typical children’s book happy ending.

331Y: Margot Forces Agoraphobic Mother to Leave Apartment

This is a 1970's or 1960's middle reader. Possibly 1980. A girl named Margot lives in a city with her mother, who has not left their apartment since the father left her. She gets along pretty well by having her groceries delivered and such. Margot gets tired of this and decides to spend the night at a library or something to force her mother to leave the apartment to find her. Not sure if her scheme works or not. A neighbor ends up dealing with the police after Margot is found; I remember her spelling Margot's name for them and telling them "The T is silent" and sounding very proud of this knowledge, like it's a family secret. There is also a boy whom Margot befriends.

331W: Magic Boots Takes Boy’s Family Away Into Forest

The book I cannot recall is a chapter book that my 4th grade teacher read with our class.

The story begins with a small family in a cabin in the woods.  Each night, they hear a knock at the door, and whoever answers the door disappears.  The reader soon discovers that the a pair of magic boots have been walking themselves up to the door, forcing themselves onto the feet of who answers, and walking them off into the forest.  Each family member disappears until only 1 boy, the protagonist, is left.  He manages to trap the boots in a pot, pours (honey or molasses?) onto the boots, and puts 2 rats into the enclosure with the boots.  The rats eat the boots and become "bewitched," and the boy stands on the rats and rides them into the forest to find his family.  He is led to a troll or giant, but I cannot remember how the story concludes.

Please help!

331G: Paranormal Handbook For Kids

I am looking for a book that I read when I was about 7. It was probably published in the late 80s to early 90s and was basically a paranormal handbook geared towards kids. I would check it out from the juvenile section of my local library and it featured directions for basic ghost hunting and how to test ESP. It featured Shel Silverstein-like illustrations of kids doing the experiments (you know, that line art style that was so popular in the 80s). It may have had any (or none! how exciting!) of the following words in the title: paranormal, extrasensory perception, ghosts.