Finally got my hands on some Automatic Binding Bricks from Bricklink. : r/lego
Automatic Binding Bricks - The Oldest LEGO Sets - General LEGO Discussion - Eurobricks Forums
Automatic Binding Brick | Brickipedia | Fandom
Unofficial LEGO Sets/Parts Collectors Guide - The 1950 Kindergarten LEGO set... one of the most wonderful and colorful LEGO sets I have ever seen. The regular 700/1 (largest), 700/2 and 700/3 Automatic