Just an idea / part 3:

It is also possible that the solution is a combination of data from the blockchain and brute forcing. The nonce values (LSB) of Satoshi's mined coins have a range 0-58 but 10-18 are missing. That could be the range for brute forcing.

Here you can check the nonce values: https://medium.com/@mytechmix/the-mysterious-19-79d0f338a06c