Could be hand drawn.
Small unimportant things and happenings are so crucial to the boy, called Hamish and his friends.
Set in time pre digital. No phones, social media, gaming.
Think Harry Potter without the magic.
Old fashioned desks, fountain pens, school uniform, merit badges, sweets and chocolate.
No running in corridors, no talking after lights out etc,.
Boys slept in dormitories of 8 boys. Always a Dorm Captain who was a senior boy. Sports big part of school life. Winter - football and rugby. Summer - cricket and athletics.
School chapel attended most days, Hamish in choir.
Traditional values. Masters and lady teaches dressed in corduroy suits and sensible skirts.
Latin taught and school would have had Latin school motto - not sure what!
Each child had a hard sided chest like 'tuck box' with his initials and his personal possessions inside - cricket ball, puzzle book, pens, pencils, photos of home, stamps, writing paper, football sticker book, small bouncy ball, dictionary.
Think 'Just William',etc.
I see the cover being 'old school' style with a nod to the past, 20 yrs past, not 50 yrs.
Uniform in untidy heap on floor with school tie, cap, shorts etc, in pile.
Tuck box with items all spilling out.
Motto of school somewhere.
School desk, old fashioned type with flip top, maybe exercise books and text books on top.
Pair of broken glasses.
Words used by teachers back in the day like 'good effort' or 'try harder' or 'read the question'.
Harry Potter is a good reference point.
Font Style. Hand written in child like hand writing - perhaps.