Dave,
Bob, from Altoona Model Works, said the door "opening" was 3.6 inches, but you used that at the front of each stall as the stall width in your diagrams above. I have to believe there's some space between each actual door for building and door support. I'm going to bet the actual stall width is closer to 5 inches. Then, you need to center the doors in each stall for actual track alignment to TT.
Chuck
