I won't want to discourage any one but I think you are right, the puzzle has remained unsolved for this long amount of time shows it's either a fake puzzle or wrongly presented, although this my first time to see it and I was about trying it out till I discovered how old it was.

Yes puzzles like this with very juicy prizes are meant to be a bit tough but not to the extent of it being so difficult that it hasn't been solved for this long period of time.