Those two strong magnets are the way to go, that nail trick works on lath and plaster every time once you get a feel for it. I keep a couple of the little rare earth ones in my pouch and they beat any $40 stud finder on old walls, half those gizmos just light up on the keys and wire mesh anyway. Only tip I'd add is drag them slow and mark both sides of the stud so you know where center is before you drill.

Four years of dust felt, you vacuum that thing out?

Did you also sit in a hot yurt while some guy told you your dead grandma was trapped in your colon?