I still remember an episode of Blue Peter where they got you to make your own Tracy Island. I vaguely recollect blocking the toilet with toilet paper as you needed the inside of a toilet roll for part of it.
Howver the toy Tracy island was out of stock - demand exceeded the supply. With Christmas rapidly approaching and a lot of kids about to be unhappy, the “build your own” program lodged in the national conscious - everyone knew Blue Peter, it had been running for decades with its sticky back plastic and one they made earlier.
https://www.discountschoolsupply.com/arts-crafts/arts-crafts...