Looking good Paul ! Although the novelty of building wears off during construction you are going to be thrilled with the end result. I am going to be relocating my obs in 4 weeks time and am not looking forward to it at all. I am going to have to dismantle the whole shed screw by screw, lift the slabs and cart it all 100kms to my new location and then put it all back together again ( I hope

). I also have to move my furniture etc and I'm getting a bit old for this stuff.
However the benefits of dark skies are going to more than compensate for the effort.