Andre, your account of the advent of the Diesels that did it on the KC&G is so realistic I was sure I would find the railroad listed in the Official Guide. Imagine my disappointment...
My planned M&G won't end with the 50 odd mile former Katy branchline. The Greenville Group which will rebuild the road will go on (at least in my mind's eye) to expand, much like the Genesee & Wyoming did. One idea: Revive the Missouri & Arkansas Railway. I fell in love with their "streamlined" Doodlebug that graced the rails before the railroad gave up the ghost after reading the book that was published about the M&A.
Looking forward to your continued progress constructing the KC&G.
Note: The Malarky "up yonder" was modified on 2/24/21.