Note: As of Game Update 56, this quest should no longer require you to harvest mantrap roots. You should be able to acquire them by any means and the quest will update. Please note: this will only take affect if you were not currently on that stage of the quest prior to GU56.
3 pieces of clay (From clay golems: there are some on way to lab but other golems in zone will also update)
5 blacksmithing materials (in the room with the blacksmith also near the lab, clicky updates look like pots of smelted metal on ground)
5 alchemical materials (in the lab, you need to get into secret room, head into library area under stairs, go to table furthest back click candle on table to open bookcase secret wall look around in there for bottles that are clicky updates. candle on top of bookcase next to door reopens wall).
Return to Gimble Tinkerton
Go to Chelsith and gather goo from the leviathan's excretions.