I am indeed serious.
I completed all except for the little sister ones because those were pains in the backside. For those, I just pressedShift + \, typed in 'lionel' and pressed Enter.
The others I can guarantee I did on my own. My favourite were the ones with the tankers and the Switchy 5000 puzzles.
I also finished them a few years ago, because that's when I got them.
Kieran.