In my fellowship (The Gammon Cube), we have a Crowded tournament every month (Around the 25th of each month) [I have sent you an invite to that fellowship]
For the Main Tournaments, you will probable have to look for "all game" or "all gammon" tournaments, not very often does someone start just a Crowded tournamnet.
.... but you are a Rook now, you could start your own Crowded tournament! :-)