The two Types of Conjurer's Garb are as follows:
A. No Luck - comes from Harbingers
B. 140 Luck - Came from the event arc that the Harbingers were part of, but were NOT from the Harbingers. Instead, you took the blue crystals (same graphic as the yellows used to summon the Harbingers) to certain dungeons, were there were cursed Gypsies there that had changed into monster types.
You would use the blue ones on the cursed gypsies to cure them, and it a random high double-digit number of the blues to affect the cure. The lucky person who applied the LAST blue crystal needed to cure the Gypsy, got the CG with 140 luck - everyone else working it got diddly. A few hours later, the Gypsy would revert back to monster, and you could give it another go.
Some shards had people camping stealthed at the gypsies, trying to sneak in the last few and "highjack" the work that others did. Other shards didn't have that problem (for example, I thing I got something like 5, 6 or 7 of the 140 luck ones, just going there and doing them all at once - no one tried to "Steal" my work, and if I found someone there, I waited until they were done (if they got the robe, fine). Hell, I even got one robe on my first crystal after someone ran out, and I GAVE it to them.