I lost my password. Made new password. Found old recovery key.
I found my old password Firefox recovery key after I already changed my password and got a new recovery key. Can I use my old recovery key to get back all the things (eg bookmarks) that may have gone missing with the switch to a new password?
Wšykne wótegrona (1)
No, once you reset the password then all data on the Sync server is purged and can't be recovered and you need to create a new recovery key for future use.