I read that there were four = Russia and UK too.
The Bank of England and the US Fed work together on everything, or at least they used to. I can't imagine the Brits doing this. As for the Russians, why do it this way? I'm sure they have numerous long standing secure rat lines into Switzerland. That is too much money to entrust to a couple of unescorted yahoos.
Personally, I think the bonds are fake. This presents an entire set of new problems.