It's been a while since anyone has posted on this, but just in case someone is still interested in this topic... Today while fighting the usual battle of the locking diffs, I determined that in fact switch "A" in the picture above is the Transfer case Neutral switch and switch "B" is the L4 switch... The L4 switch being bad in my case and much harder to remove than the neutral switch.
I also came upon a process for renewing these "bad" switches which has worked perfectly on two switches I've tested it on - see the following link:
CDL Sensor/Switch Initially my bad switches had resistance readings of several megohms. I did not take to hitting the switch as described in the link; rather I tried to work in some 91% isopropyl alcohol around the plunger, I then connected the switches to 1 amp current limited power source (the 9V battery idea probably works just as well) and operated the switch 20-30 times. When done, I measured the resistance with a ohmmeter and amazingly both switches exhibited contact resistance of well under 1 ohm. Call me impressed...