I have done a lot of research on NC surgeons and assistant surgeons about the proper rank to wear. Early war regs call for a frock coat with federal style shoulder straps for all staff officers to include medical. I put the captain's shoulder straps with the M.S in the center to distinguish me as medical but my question is once the transition to collar rank is made, are there any distinguishing ways of showing me as medical service other than the green sash if/when I wear it?

Also any other confederate medical info or research material would be great. I am always looking to improve my impression. Thanks