To follow on....
I know you'll get this Mike - my comments about your post were not intended to shoot you down - more calling into question Blandford's comments on the ROC which I would describe as
Enthusiastic rather than accurate! I like the lateral thinking - and would love it to be correct and backed up somewhere in a long lost publication /report /AM order. (But I fear there is a very slim chance of that).
Harlequin - I like the thinking! I have in the past even tried to identify the person in the picture (to no avail) and looked at other options too. I do not discarded what you say, indeed the text on the front of the No.6 Group Museum
webpage does elude to there being a badge in existence:
"By late 1942 there were 191 branches of the [Royal Observer Corps] club. Observers/Members were also lecturing/instructing the Army, Air Force, Navy, Home Guard, Air Training Corps, and Spotters Clubs in order to pass on their knowledge.
Recognition tests were of three grades; Basic, Intermediate and Master. For the latter a badge showing the plain view of a Spitfire was awarded and worn on the arm. At the end of 1942 it was announced that the ROC club had to be disbanded and the journal to cease production, and recognition cards were to be stopped".
However my inclination is that badge referred to here is indeed the printed one instituted Dec 1942 for the ROC not one for the Royal Observer Corps Club itself.
Lawrence Holmes collated some information in 2010 for the ROCA Heritage Team (Notes and Papers for the Hearkers Club and the Royal Observer Corps Club). This might be a good starting point?