The info I have came from the Library of Congress, Wash. D.C., they may have something on line, don’t know. If I recall correctly, it was Congress that passed the 1863 Guidon law as recommended by the Military sub-committee. After passage the War Department issued a General Order (don’t have the number), then it would have been up to the Quartermaster Department draw a pattern and commission the contracts for the Guidon’s to be made.
Try calling them, If the museum does not want to share the information with you on the size of the stars, try google books.
I can send a copy of the regulations, there is a research fee, contact me direct via email. tom@Piedmontflag.com
Happy Trails!
Tom Martin
www.Confederate-flags.org