Unfortunately, there is no way to fix the recovered save.
If you zip the recovered lsv file, does the size decrease significantly? It is already compressed, so if zipping it reduces the size by very much it would imply that there is missing data (file recovery programs will fill in missing data with zeros, and in some cases a restored file may have the name and size, but be completely blank).
I don't suppose you have any recent backups of your My Documents folder?
Do you have Windows shadow copies
enabled, if applicable? Try right clicking the overwritten save folder, or the 'Story' folder, select Properties and (if available) switch to the Previous Versions tab to see if there are any copies.
If applicable, Steam keeps a copy of the profile in its install folder, to use when syncing, so you could try searching there, as well (Steam usually syncs automatically when exiting the game, and restarting should always trigger a sync, if required).
For future reference, with the Steam version you can download (or check / delete) online saves using the program Steam Cloud File Manager Lite
), but in a case like this it would only help if used before steam synced. You need to be logged in to the Steam client and have the game's AppID (435150).