Hi.............
Firstly what a really great piece of story telling you've produced - captures and promotes a lot of tension and atmosphere.
Regards your discovery of the under represented damage to the street lamp!........ Well you claim or allude to it being a simple piece produced at little cost, so you could just let it slip by knowing that you'll probably be one of its few observers to ever know any difference.
However, the effort put into the build is where the real value lies, the integrity of your understanding of the scene has now been re-focused, but yet your natural eye for an excellent compositional piece means to change its strong outline by reducing the height would I feel also reduce the sense of drama within which you've enthused the scene!!
My counsel would be to straighten the lampost - repair and reduce the amount of damage, but perhaps take onboard your eye witness accounts and place discretely around the piece more subtle damage such as shrapnel and bullet impact or ricochets.
Just my thoughts as an interested onlooker................ Longbow.