(10 years ago) Wow, this is a GREAT level. It took me 50 tries to finally solve it (and about 20 to even come ''close''). My last problem was a 2 off, but I managed that quite quickly (about 3 tries more). :)
EDIT 2023, 23rd June: this time I had a serious problem with the 4 off. Even after reading yokosooo's comment, I thought my problem was different. But after solving I KNOW that it was the same. LOL
Very tricky and interesting. Goes straight to my ''mind jewellery'' collection.
Interesting path!
To Devildude1, I also got a 4 off before -- my mistake was that I approached the lock near finish too early ... Not sure if this gives you any idea?