Michael, I just found your topic, and I must say you are going in a great direction with this layout. Congratulations on having the space to build it. I went through a long period without layout space while our daughters were growing up, and now that the last one is married, I have gained a room for my layout build.
One thing, I can not see the first two images, which I think are your current track plan from your reference. The photographs of your step by step construction look great. I used GarGraves Phantom Line track, Ross switches, Midwest cork also. I wish now I had used the Ross bed for under the switches since cutting cork to fit properly is a challenge for me.
I was wondering how you were going to access, but then I read on and saw the many access holes to the upper levels. Bravo! You look young enough to crawl under and pop up for years to come. I approaching 64, on the other hand had to build an around the room layout with a lift up access bridge to the center operating area. My plan in SCARM called for similar grade and a 6" level separation. In practice, mine ended up at about 4% and 7 1/4" level separation. Testing has shown that that grade works fine for the short trains I will run on the layout.
I like the furring strips for the backdrop. My layout room has one brick wall that I didn't want to put holes in, so I have mounted the backdrop on braces attached to the layout and notches cut in the hardboard that slip over the joists. I didn't get it in from the beginning, so some places were a bit of a challenge. I advise getting the backdrop up soon. You may be able to crawl on the layout, the framing looks quite strong enough. I am not able to crawl up on mine, though it would easily hold my 170 pounds.
I am really looking forward to seeing your progress!! It looks like it will be a wonderful layout to build and operate!! Congratulations!!!
