The last number is supplier or suppercission code, there are more than minor differences like ignition switch type and location, connector box or rats nest in headlamp shell, one fuse of fuse box, "safety" starter interlock.
The switches are actually no never mind and most will fit any model
for the K3 you are looking at re-furbing the one you have i'm afraid and hope all the plastic blocks are OK as you can replace the spades but cant get the blocks