I've seen this referred to as representing Luther Blanchard as well as William Diamond. Which one is it? I don't know if it matters. They both were about the same age (16-19). However, Luther Blanchard (age 18) was injured during the advance on the North Bridge and later died (as a result of these injuries?). Perhaps I know the answer since Diamond was a drummer and Blanchard was a fifer.
According to the FAQ page, it is referred to by several names: William Diamond patch , Luther Blanchard patch, young patriot, and the youth patch. Thanks, Oz.