Check with John Young at Young Custom Ag Service at Spring Valley Il.Ph.815-663-3943.He is the guy who remodels 820's,and probably forgot more about them than most people know in the first place.
Young's Custom Ag Service sells a new style narrow divider that I think is even better than the 1020's. Their number is 1-888-434-9820. Shoup also offers a narrow divider for 820's but I have no experience with them.