Obviously, I didn't make it yesterday, but I will be looking for you doing this. I will also try to drum-up some peope from DWG who are interested. If you went back to running it every night, I would hop in whenever I got on. (Even though that wil probably be later than when you start)
As for flagging:
You need to run all 4 of the Orchard quests, Ghosts of Perdition, Fleshmakers Laboratory, Inferno of the **** and Desecrated Temple of Vol to get sigil pieces.
There are 4 static pieces (pieces 1-4 drop in the order above) in the end chests. They may or may not drop you in any given run for you, unlike the stones in the Vale. Therefore you may need to run each of them several times to get the static pieces.
In addition, pieces 5-8 drop randomly in the 4 quests. You will need to run these quests until you can get all four of them. The good news, most of the people you will be running with will already have the pieces and are willing to transfer for them to you. This is because you only need to complete the sigil once and the pieces are bind on acquire with no other real use.
Once you get all 8 pieces, you talk to the guy in the Orchard, he opens the pre-raid. The pre-raid has 4 different "sides." You can only complete one per run, and each one has one of the end bosses (hyped-up) from the 4 pre-reqs. You need to go through and do all 4 sides to get flagged for the raid.
Once you've gone through all that, you're flagged.