“Kyrie, Gott Vater in Ewigkeit”, BWV 669 registration: right hand - Cornet, left hand - Principal 8', Pedals - Principalbass 16', Majorbass 16' and Fullbass 8'.
“Christe, aller Welt Trost”, BWV 670 registration: solo voice was played with Trompette 8' and Octave 4'. Right hand - with Principal 8' and Octave 4'. Pedals - same as before plus Subbass 16', Flautbass 8 and Flautbass 4.
“Kyrie, Gott heiliger Geist”, BWV 671 registration: Organo Pleno - full principal chorus with mixtures and 16' in the manual and with Posaune 16' as well as Subbass 32' in the pedals.
Let me know your thoughts while listening to these chorale preludes. The scores with fingering and pedaling are available here, here and here.