Larry,
a low-resolution scan of the only photo that I have ever come across of the I./JG21 Stab a/c during the first six months of 1940, using Bf109Es in early 1940-camouflage is attached for your ready reference. Unfortunately, the Stab markings are not visible. The photo was taken from a Raumbild-Verlag Otto Schönstein book Fliegen und Siegen, which can apparently be procured here
http://www.usmbooks.com/raumbild_luftwaffe.html . I happen to have this photo in original if you need a good quality scan.
As for the Stab III./JG54 aircraft a nice example can be found on David Weiss' excellent website here
http://www.messerschmitt-bf109.de/ . Should be able to send you a direct link via e-mail.
Regards,
Sinisa