Awesome is the adjective that comes to mind when I consider the brainpower brought to bear on the problem. I contributed a few ideas, unfortunately none of them the right ones! However, after after a massive effort the breakthrough came and we were presented with the second half of the puzzle. This was much easier, though there was some controversy over the value for one letter. Today, at the agreed time, we came together to make a swift and joint FTF of the cache and to retrieve the formula for "A mega-puzzle of many parts", which we went on to retrieve.