I forgot to ask a couple of questions about the recorder you inherited.
1) Are there any markings or stamps on it that might indicate who made the recorder or what brand it is?
2) Does the lowest finger hole have one hole, two small holes, one pad operated with a key (i.e. lever), or two pads operated with two keys?
3) Are any of the other finger holes fitted with a pad operated by a key?
If we know the maker/brand, we might be better able to offer guidance as to whether the recorder is worth struggling with. Also, if the recorder has a pad on one or more of the holes, those notes and any notes below them would be hard to play if the pad or pads had dried out and no longer sealed the hole properly.
–Dick–