Something smells fishy here. In 2021, you were missing 29 characters of a 488BTC private key. A few months later, you were offering your services to "recover easily". Last December, you had "a friend" who can't access his 2500BTC bud didn't know how to do this thing with btcrecover.
If any of this is real, your client/friend should be talking to [url=https://bitcointalk.org/index.php?topic=240779.0]an expert instead of you.