London Road Cemetery, Mitcham, CR4 3LA (Google map).
In the Commonwealth War Graves section, plot 14, of this cemetery there are three gravestones for Auxiliary Firemen who died at the Surrey Theatre, on 10th May 1941.
The Commonwealth War Graves Commission (CWGC) website doesn’t include the details of these graves in their list of the war graves at this cemetery, because, as commented below, they are not classed as full war graves. The three gravestones in plot 14 are shown below, the sequence being from left to right as viewed from the path, which leads from the entrance in Victoria Road.
E. G. Pepper, aged 32
E.F. Robinson, aged 35
C.A. Elliman, aged 37
A pdf plan of the the layout of this cemetery is available from Merton council’s website.
Mitcham History Notes 
The clipped corners on the headstones show that they are not full war graves. AFS I think come under civilian war dead, CWGC maintain the rolls of honour in Westminster Abbey, but not the graves themselves.
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Thanks David. I have changed my post.
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