The only PG that I remember winning a tournament to gain an HQ was Cipher Nex, though they haven't claimed their HQ due to inactivity. The RH has also technically written out a thread to build an HQ, which would be enough to gain one, but hasn't claimed it again due to inactivity.

The CT was the pg vs. pg tournament that awarded the HQ.

I'm, honestly, not sure what the ruling on owning more than one HQ is. I know that if a clan with an HQ attacks and beats another pg with an HQ than they take over the other one, technically having 2 hq's. I'll definitely ask about what the rewards would be due to owning two HQ's though and get back to you as soon as possible.

I'll get back to you asap.