I'm not in StuyTown, but your description checks out as possibly what's going on here, maybe with a newer layer of drywall slapped on top. Thanks.

These are really cool. We of course have plastic wall anchors here, but I've never seen a fancy multi-use anchor like this. I'm wary about how much weight it would hold, though, especially since the Amazon listing doesn't seem to claim anything in that regard.

Thanks. What would be an appropriate anchor? Ordinarily for masonry I would use something like Tapcon screws, but this seems like it might be too brittle. Do you think the lag screw + lag shield approach would be appropriate?

I own the place. Doubt the super or coop board would know.

Thanks. Yes, it's an interior wall with another room on the other side. And I own the place—would not be drilling holes this big in a rental!