My knowledge of the ROC is basically what I have read on the forum or picked up via Google but I enjoy digging around for information ...... and solving 'mysteries' !
As such , I tend to think "outside the box" and don't rule out anything until further evidence disproves a theory. Regarding the idea that the badge may be an ROC Club emblem/award , if these were commonly awarded why aren't there photos of these being worn or surviving badges available ?
I did find a 1941 clip of the ROC which I found interesting , you've probably already seen it but I'll post a link in case others want to see it.
Royal Observer Corps