As a puppy, Koji was pretty shy with people and strange looking things - lawn ornaments - christmas decorations, etc. I spent a good deal of time introducing him to people, having them give him a treat - and also introducing him to lawn ornaments. My neighbors think I am crazy - when I go up to a concrete staue and tell Koji to "Say Hi". He is much better now, but every once in a while - he gets freaked out by something.
My puppy class taught us a game called "smell it". They said it was a good way to help a fearfull dog to be more confidant. You play by getting a variety of different objects (really whatever you want, we used a coffee cup, a water bottle, a brush, and a shampoo bottle) and asking your dog to "smell it" one by one. Each time your dog smells the new object give them a small treat. Once the dog gets the hang of it you can work up to bigger objects of things they are afraid of. It's supposed to help them realize that whatever the object is they don't need to be afraid of it and by being brave and smelling it, they get a treat. I don't know if this will work for Joji but I thought it might be worth a shot.
I actually used a game called "Say Hi" - and would hand a treat to a willing stranger and instruct Koji to say "Hi' to the stranger - and then he got a treat from the stranger. So now when we see anything that he is shy about - I just"Say HI" and he knows its safe - and he'll usually get a treat or a 'good boy'.