I think I have the plastic **** for the for your lockout I have to check I have one from a prevously owned truck Ill check tonite.
As far as the fuel sending chip don't know
For the switching problem look at the diverter it should be right in front of the second tank with wires going to it,I am not sure how they work but I think you should be able to look at it and figure it out. they need to be switched often to keep them working properly.The truck I have the lockout from had the same problem and the previous owner bypassed it and I left it.

Wayne