The turn-in for this quest is after speaking to Sprockfuddle. To get the rest of the steps you have to speak to him again and he'll give you the quest "Trade Secrets," which contains steps 2-10 listed below.
Sprockfuddle is located in the Smuggler's Grotto found by going underwater at ( 882, -26, 31 ) /waypoint 882, -26, 31 and traveling into the sewer entry.
Speak to Vernon Tinworthy ( 807, -14, 42 ) /waypoint 807, -14, 42, on the top of the stairs (third floor) of Fish's Alehouse. He doesn't trust you, and sends you out to speak to several other people and to gain their trust.
Speak to Mary Dillon ( 801, -23, 60 ) /waypoint 801, -23, 60 downstairs. Avoid asking about the shield, and instead console her about Thierry.
Head to South Qeynos and speak to Thierry Dillon ( 620, -16, 225 ) /waypoint 620, -16, 225 wandering the streets. Choose the following in conversation:
"Sounds like you're a compassionate person. And a smart one!"
"She's not a very friendly sort."
"Ellinnea couldn't help boasting; a transparent effort to put you down, really."
"Your device would be much better, I'm sure."
"You're a genius, Flizgibbert!"
Head north and speak to Arbuthnot Jumroller ( 788, -23, -529 ) /waypoint 787.63, -22.68, -528.55 In the Halfling area of the Qeynos Province District to the north of Towser. Praise Towser and ask about the truth potion.
"You're friends with Towser Flizbiggert, aren't you?"
"I hear Towser's a great teacher"
"I met him through the design contest"
Head to North Qeynos and speak to Jo Ironshield ( 284, 17, -167 ) /waypoint 284, 17, -167 on a hill just north of the bank. Grill him and get the truth potion.