I've searched the 0201010420 trailing bytes and checked hundreds of private keys manually but with no success as yet. I could see they were bitcoin core keys with the data and text surrounding them. I suspect that the private key I need is encrypted and there are hundreds of those as well, plus mkeys. I noticed that each ckey marker 000104636b65 79 is followed at a point later by the trailing byte of 30 as discovered and shown in HCP's example. I'm thinking that maybe the bytes following 30 is the encrypted key and the public key is between 79 and 30 maybe?