Hi James,
I'm sorry to have to report what looks like a finding in Makeobj-Ex.
As you know, I modify the source for the industries. As it turns out, when I compile the industries (even un-modified source) using Makeobj-Ex, this triggers that the 'industry extends it's chain' event never happens in my game, all industry expansions are new chains. Since this does not happen with either Pak.German-Ex or with Pak128.Britain-Ex as you compiled it, and like I said an unmodified source displays the same problem, the problem appears to be Makeobj-Ex.
As a sidenote, is my assumption correct that you use a different method to compile Pak128.Britain-Ex? If that is the case, I might want to try that one.
As usual, please don't hesitate to ask for anything that might help you.