I am of a different opinion. I wouldn't have suggested a close up of the bolts because thats a typical thing to do to a rusty object, such as this. Much more importantly tho... you wouldn't have have captured that white line, dividing the two contrasting textures. This is the most important feature of this picture imo and glad you decided to include it. I agree with you, the bolt shadow on the right is noticably cropped, but as an abstract image i kinda like it as it is... i would be tempted to add more shadow/highlight detail... and would have considered changing the angle maybe.. but that is all i'd change.