Hallo Kari -
Off hand, I'm afraid I can't think of any RNR uniform photos of Murdoch - at least none that have been published. I could be wrong, but none immediately come to mind.
I know there are photos of Smith, Wilde, Boxhall, Lowe, Lightoller and Pitman in their full dress uniforms, and of the latter four in their daily attire. I'm particularly fond of an informal photo of Boxhall taken on a torpedo boat during WWI - it gives a good idea of what they wore going about their daily duties. There's also a superb photo of Harold Lowe wearing his rating's uniform, before he received an officer's commission. But Murdoch photos are thin on the ground, unfortunately. Hopefully someone will be able to produce one, or I might recall one in a private collection.