Ontario Grain Drill 850 - how to clean it out?

[lineage]

Hi there,
We've got an Ontario grain drill, wooden box, and are wondering if there's a way to mechanically, completely empty the grain box when we've finished seeding a field. Must we vaccuum it out every time? It seems to stop feeding grain through the cogs once it gets down to a certain level, is there a way to open up the box to just let it fall?
Thanks

[MIKE R]

Can you just open the feed controll all the way open. If not vaccuming it and storing out of the weather is the only other way I see. Welcome to the forum.