Here's an altered version of the plans with the 7+ posts. I'll keep modifying it as we discuss. It's high time this one was sorted out once and for all.

http://doctorwhoscarf.com/drwho/s18dev.pdf

I'm working on a 3D model of the TYJ box. I was using the previous plans with the 4.5 flat and 6.5 measurements for the posts, but having discovered the recent amendments, I'm trying to re-jig it. My problem at the moment is that I can't get to a 7"+ measurement on the posts using the info provided, I seem to be .125" short!

   The flat is 4.25 with an inch either side (6.25) plus 0.25 protruding on one side and 0.375 on the door/wall side (6.875)? What have I missed? I can't see where I've gone wrong.

Just looking at the top view on the rhs of that pic, what does the 40" measurement relate to? Can't be the sign box inside dimension. Anyone?

I think it's the roof. 45 is the lower step and the 40 is the pitched top.

You know what? I think you're right. I didn't look down that far. The blue lines should probably continue down further to the roof section involved. I would have put the roof dimensions on the side-on view myself. Still a very handy reference... Even if it IS in inches. 

I don't mind inches, I prefer them in 3DS Max

   Just a thought here, in addition to my previous question, but as the TYJ box was based on the original (with a few alterations) does this mean that the plans for the previous boxes will need altering? Or did they both in fact have slightly narrower posts?