Hello,
Photos of Bf 109 G with JG 300 RVB and short black horizontal bar are known, but what about this one with a yellow or white short black horizontal bar over the RVB? I know of several examples of the short black bar, but that is the first one I have seen of a white or yellow bar on a JG 300 aircraft:
https://www.jg300.de/wnr-151686.html
Roger