I built mine exactly like the original last night. Works awesome! I thought that I would have to press the lever on the sprayer to get it to flow, but the flow starts as soon as I open the tap. Either way, works wonders!
If you saved the white plastic gasket from the original assembly, if you insert the wide end of that inside the A176 before threading it onto the sprayer, the other end will seal against the "trigger" plunger, making it functional...
Cheers!