Nearly certain this is RNG, but on the off-chance there's I've missed something..
Doing the IA Daily every single day for over a week, off and on for a week or so before that. Sometimes doing a few more Arcs, but not usually.
Found a ton of great furnishing plans in the lobby. Got some great pieces of the class sets.
Not a single antiquities lead, which is candidly the whole reason I'm running IA.
These are meant to come from Muniment Chests, right? More Muniment Chests, more chance for leads and just hope RNG swings onto my side?