Quote from: hercula on March 05, 2014, 11:46:59 AM

My backups are four strings, 581 characters long, representing a hex value (ie. there are only characters 0-9, a-f) and all of them start with 80.

Hex 80, as mentioned, is the start of a private key, the character "5"...which begins the private key. You then need to work out where each private key ends, which would be very simple from this point. Simply find the space character (hex 20 I think) or perhaps the null character (hex 00). Each character in that private key is either two numbers, 1 number + 1 character (A to F) or 1 character + 1 number as per hex representation.

When you reach the space character, you've probably got the entire private key which needs to be converted to a string to import into a bitcoin wallet.