Added assembly alignment pegs to the cover and mating holes in the body for easy glue up and strength. Tested at 140% scale. Thanks to boksbox for the original work.
Feel free to remix this remix: https://www.tinkercad.com/things/3hVfBgMLKdZ
Printed scaled to 140%; perfect for adult hand.
Started with boksbox original. Added alignment pegs and holes in TinkerCAD.