He will get 10% as agreed.

The owner (a former miner) doesn't even need these coins. He splitted a large account (147PsLmcSFhEUEjAerYY6VEH6Z6kCrDwyK) and transferred back in 2017 to three addresses 500 BTC each. Two of them he hass access to:

1HtQwoguFkvMynK1NyDhh1weHjrMyDAKU
1Ek93YBu22kMJ43GhbTy13dYnckcbZE4xu

But for the address 1PfNh5fRcE9JKDmicD2Rh3pexGwce1LqyU he lost a part of the private key as you can see on the diary photo. And he agreed to make a challenge, where people can participate to find the WIF.