A very Nice clean build there Tony.
As for the photo's If your using micro mode (for close ups') and holding the camera while taking the photo's you will get a some blurring from the motion of your hands. I always take my pics using the camera's timer and a 6" mini tri-pod.. ( they are fairly cheap)
And yes the M10 had a 3 inch gun (76mm gun) and could fire HP as well as Ap rounds. In the M10 it had a lot of Balance issues with the turrent which is why they kept redesigning it.. The 90mm used in the M36 fit into the M10 turrent with no Major problem's but was about 300 lbs heavier than the 3 inch gun. which would hare required more counterweights. But with the existing M10 turrent the 90mm and the fact that the 90mm ammo was larger fewer rounds could be carried so they decided to design a brand new turrent in order to carry more ammo.