So...I take it that it has something to do with equipment and scrolls of flying?
Also, I've been finding kakis around (new fruit)
Music tickets and BGM disks, it seems and final fixes for quests.
There is also clover leaf (edible, increases luck), acorn, gold acorn (nuts for making candy), romias (some kind of cookie, maybe) and a way to exchange bgm discs for a jukebox.
According to the JP changelog, the acorn and clover are from v1.27. Don't know about the others.
im using elona+ 1.21. is it safe to upgrade with existing save game files?
Yes, it is. Probably, you would need to save in the city(i.e. not on world map).