Bit of a Necro, but Idk if you've figured out how yet - you get the items from two bosses on the map that you can get to from the river. Orb comes from the one in old Rosh pit, the gem thingy or w/e it's called is up just below the second Tier top lane turrets, in the river. They both drop 1-2 based on game length, while they always have a 50% chance to drop an extra. Don't quote me on that drop rate part, been awhile since I've read the tip for it. But where they are at and what they drop is correct.