I have to agree the walls do appear to be sight line related. I’m in favor of the idea the walls came before G3 construction and considering the G2 connection G3 should have came after G2. Unless the dimensions for G2 came from the G3 layout! (unlikely IMO)

Could be a foundation layer for G3 was laid out then the walls built but I don’t see why!

I’m not sure what you meant in your first reply about scale? Did you mean you want 45 degree lines drawn from the corners of G1 or do you want lines drawn from the G1 corners to G2 corners down to the walls?

The size and placement of G3a should be correct because of station mark D and the size of G3b and G3c should be correct but I’m not sure about their exact placement! (need more data if anyone knows!)

RLH