Sure. I never had a chance to assemble Lego from those days, but from unboxing/assembling videos [1] it seems that the manuals were either hand drawn or photos,

Sure. I never had a chance to assemble Lego from those days, but from unboxing/assembling videos [1] it seems that the manuals were either hand drawn or photos, so definitely it was a manual work. 1. https://youtu.be/xuJ2OulhC1M?t=564 https://youtu.be/xuJ2OulhC1M?t=564