Have a look at this clip.
At a guess it's missing the telemetry wire.
But not 100% sure.
You could just put them on and see what features don't work.
maybe they are just things you don't use.
https://www.youtube.com/watch?v=J_pLCGmSW2c
and this one.
https://www.youtube.com/watch?v=KTGlZSgtKVA