I can jump in here. A long time ago on a far away train layout, there was an evil helix. When the helix worked all was well in the galaxy. When the helix did not work well, then the galaxy was pissed. One evening after three nights of relaying track in the evil helix and having little if any success, the galaxy took a chain saw and cut out the evil helix and threw it into the front yard. The evil helix spontaneously combusted and was burning quite well until the galactic police arrived and requested the fire be put out. So I was left with a two level layout that no longer was connected and a really big hole in the back end of it. So I added a second level which resulted in longer mainline runs and a new industry and a long climbing horse shoe kinda curve that connected the second and third levals together. After leaving the curve unadorned for a couple of years I stumbled upon a box of resin mobile homes at a train show. The price was right, 30 bucks, and the rest as they say is history. The whole area is known as Nob's Hollow and as you can see the top mobile homes are kept in good repair. And yes those are Hot Wheels, Matchbox and Johnny Lightning cars in use. I am cheap, I like them and its my mobile home park.....