My grandparents have these old toys in their basement, from when we were kids, and also from when our parents were kids.
The other day, I was watching a video on the history of LEGO and learned that the LEGO brick was hollow when it first came out. Inner tubes were added later to make builds stronger and more stable.
Knowing a box of old LEGO was stored in that basement, I went and checked in the hope to find some. And I did. 🙂
Bonus: I also brought this cool sorting tray from 1972 home. Its item number is 793.