WOW!!! Great plan, it does pay to dream, wait, think, dream, wait and think some more! After more than two years of the same, I begin today and am encouraged by your thoughtfulness and thoroughness - it pays!
All of the preceding comments from the more experienced and wiser Ogaugers are on-the-money, especially those regarding old plumbing, access, backdrop, more industries and old plumbing. To paraphrase lines from Blazing Saddles, Q: "You said "old plumbing" twice?" A: "I hate old plumbing!"
A quick review of your OGR Forum activity, which includes disposal of PRR equipment and replacement with B&O, shows that you are "intending toward the light." It's good to know that I have another brother out there!