Hey, @mattclarke.
re: out of hock
Yeah. I'm sure he'd rather get his 75 million back, and if for whatever reasons it doesn't appear imminent voluntarily, that would be when some other means of doing so would happen.
re: how much
It would be good to know, if only to allay fears of using that back door.
I was thinking up until this last sell off that maybe he already bought a significant amount of STEEM, but if he did and is now selling it, that doesn't help him lock it up to vote in witnesses. :)