School or workshop stool

This charming stool made entirely of solid wood is functional and very sturdy. It moves easily with its opening on the seat to slide your hand in. Which makes me think that it is probably a school or workshop stool from the first half of the 20th century. It is slightly flared towards the bottom for good stability. It is in very good structural condition, no weakness, nothing moves, it will still be there in 50 years! But obviously it also has the patina and marks that testify to its age (despite careful cleaning): various marks and stains (paint, water etc.), no more traces of finishing on the seat which shows that it has been used a lot. It measures 45 cm in height, the seat is a square of 30 cm on each side, the base forms a square on the ground of 32 cm on each side. It weighs about 5 kg.