I had lunch with Laurie on Friday, the first time we've caught up in months. He showed me this puzzle when I first moved to Busso, nearly 4 years ago. Neither of us could work out how it was done. Somehow a nail has been driven into a piece of wood from an impossible angle/position. I've pondered it a few times, and examined it closely looking for some tell-tale sign of how it was done, all to no avail, so I did something for the first time, I rang the number on the bottom of the puzzle to get the solution. Roger answered the phone, in Tasmania and worked out pretty quickly why I was calling. He revealed the secret to me and I must say it is extremely ingenious and quite surprising, certainly not something I would have thought of on my own. Mystery solved I returned it to Loz over lunch.