Good catch on the brown-and-white shirt that Kramm wore in the episode and Peter wore in the Valleri performance.  Kramm also wore the blue cloud shirt in the episode that Davy wears in the performance!  And Peter wore the blue cloud shirt in One Man Shy, and Davy wore the brown-and-white shirt in The Prince and the Paupers.  And Kramm's pinkish-red shirt with the toggle-shaped buttons had been Micky's in The Chaperone.   

Here's the shirt-swappin' timeline (with photos) on my blog: http://bluemoonalto.tumblr.com/post/57199104422/cellomouse-you-were-right-about-that-pink-shirt