Corrupted Numbers file won't open
I was working with a Numbers file (version 10.1), Mac OS Catalina (10.15.6), that I keep on an external drive. The drive fell off the desk and physically disconnected while the file was open with unsaved edits. I got a warning that my recent edits might not be saved. When I remounted the drive and opened the file, what opened was a different file, not the one I was working on. If I close the file, quit and relaunch Numbers, and search for recent files to open, the same wrong file opens when I select the name of the apparently corrupted file.
If I do a Quick Look on the corrupted file in the Finder, the correct content of the apparently corrupted file is displayed including some recent edits, so it seems like the file is "there" but I can't open it with Numbers.
Any ideas on how to save this file? (I can go to a Time Machine backup and reenter data, but I'd rather not if I don't have to.)
MacBook Pro 13″, macOS 10.14