Thanks, now I understand what the blocks are for.
Looking the rightmost pic in post 80, the spacing of the lights holes on the sides of the cross are closer than the spacing at the bottom of the cross and it appears the length of the side cross is shorter than the width of the bottom cross when the should be equal size. Comparing it to the Starlog blueprint and pics, it looks the L and W are supposed to be equal (and the light spacing).
I see a slight modification will be needing done here.