Well it looks like you still have the harness and the CAS is still their. They obliviously didn't do a proper carb conversion. I think you just need to find

-460cc high impedance injectors
-fuel rails with Pulsation damper and one with Fuel pressure regulator
-N351 s5 n/a Mass air flow sensor
-N351 s5 n/a pressure sensor
-stock lower intake manifold
-upper intake manifold
-throttle body with tps's

-6port sleeves
These might have been wired open notice the lack of air pump. Question does the car feel real sluggish at low rpms? Take a look right above the exhaust manifold do you see two actuators?

-TB cap and intake duct
-s5 electronic oil metering pump + lines and injectors
I can't tell from your pictures if this was removed. Take a picture of the front housing next to the water pump their should be a black box that has some oil lines going up towards the top of the motor.

-Proper block off plates for your emissions crap. BAC,ACV,ERG. 2751 Engineeering Performance

Also because the removed the air pump. Your water pump may began to slip if you don't get a Dual alternator pulley or a YOOHOO belt.