Absolutely!!! Without partzilla, doing a full engine rebuild would be impossible (instead of a massive puzzle to find all the parts across multiple websites
I hadn't actually thought to look there for the 1980 compatibility, so thanks for the reminder
That said, partzilla only lists which same part numbers were on which models, but doesn't tell you compatibility. As far as I can tell (looking at pictures and back of the envelope guesstimate measures from photos), it seems that the KZ1000s have the same mounting system with the 2 hinges and sort of loop clasp as the KZ1300, but I can't actually find anyone who's tried to swap them.
Ultimately, I'd like to get a Corbin seat but I need to make sure their KZ1000 seat pan will work with the 1300 because they won't take back a seat that they don't guarantee fit for (which they don't in this case). I could always show up at the factory to try the seat and get it fitted, but 1000 miles to find out it doesn't seems a bit far