I know of many people who have successfully completed that last puzzle in v1.0 using only the debris from the Island Events to train a Master Builder, so it IS possible! It might take a few tries, since the Island Events are random, but your best chance is to keep your tribe strong and healthy and, when that event occurs, train a 14-year-old (and only ONE 14-year-old). That way, there is a better probability that another of those events will occur in that villager's lifetime (since a single debris field probably won't be enough to turn an unskilled villager into a Master Builder).