Unknown Civil Defence 9b.S.C. Area Title

[londonclanger]

A bit of a long shot but this peculiar Civil Defence area title (assumed to be wartime) with "9b. S.C." is proving extremely difficult to identify. It follows the standard format for wartime area titles - old gold lettering inside a rectangle on dark blue. A few collectors appear to have seen it before, or have it in their collections, but so far a positive ID has not been forthcoming.

[londonclanger]

A possible answer may lie in other items sold separately to the insignia (someone was kind enough to point this out to me elsewhere). There was some additional paperwork belonging to a warden in Worcester Park, Surrey.

Worcester Park just creeps into the very north of Surrey (just south of Moreton & Morden).

If the map is correct, Worcester Park is part of Sutton & Cheam Borough (S.C.?). And, Sutton & Cheam Borough is within Group 9 of the London Region and also the Sub Group (so possibly denoted as b).

But why bother with such an esoteric naming convention?

UPDATE: I received a couple of replies to a blog I wrote on this badge. One said that Worcester Park was in the borough of Epsom & Ewell. However, another email said Worcester Park is split between the extreme north west of the London Borough of Sutton in Greater London (east of the railway line that runs through the area) and part of the Borough of Epsom and Ewell in Surrey (west of the railway). So, it's possible the above could be correct.