Efficiency

Level 1 of the Dungeon
(0, 0, D:1)
  a frilled lizard corpse
  a goblin corpse
(0, 4, D:1)
  a giant cockroach corpse
(1, -15, D:1)
  a +0 scale mail
(1, -2, D:1)
  a bat corpse
(19, 12, D:1)
  17 sling bullets

Level 2 of the Dungeon
(0, 0, D:2)
  a bat corpse
(2, -1, D:2)
  7 boomerangs

Level 3 of the Dungeon
(0, 0, D:3)
  a +0 flail (still there?)
  an orc corpse (still there?)

Level 4 of the Dungeon
(0, 0, D:4)
  an uncursed amulet of faith
(4, -26, D:4)
  a scroll of magic mapping