Nice summary Mark. In my head i keep going back to your exact "Company A" concept. Why pay top dollar with an off take when you can secure the same supply at cost by just outright buying the deposit? Even if Company A only need 25 ktpa, they can do a JV with a mining company and get their share at cost and give the other 25 ktpa profit to the miner.
What I would give to be involved in these NDA negotiations. I have been involved in several buyout situations (3 in the last 5 years) and it is very difficult, emotionally and otherwise to keep things under the 'cone of silence' (as Maxwell Smart used to use).
I can't imagine we will have to wait too much longer for some type of bursting of news.