Are there supposed to be two springs on the throttle return on a Sciricco (8v 1.8)?
No idea, but that is normally a good idea.
Only good thing about a Scirocco is the radiator. 
I believe there are two springs, I know the 16v throttle body uses two and it's the same basic design.
Well then I should probably find the second one...
You should hope to find the second one.. as it springs eternal