Bad news, apparently the 'Bag of the Tinkerers' is a backpack that has 10
slots with 100% weight reduction. That isn't worth 8000 pp to me! If we
could make one it'll likely cost us 13000pp to produce (compass). Or it'll
cost 3000pp to make and then not work (cams). Nonetheless, you won't get
any experience from it because you'd get the tattered backpack back on a
failed attempt.

Anyway, no luck yet on the other books.