I'm not currently 100% certain if this badge is WW2-vintage but going by the thread colour, backing fabric and rear it could be. If not, perhaps the local area issued them to the local Ambulance Service post war. If you know more please contact me.
The three wartime authorities in Lincolnshire - Holland, Lindsey and Kesteven - all produced a number of enamel and embroidered badges for the Civil Defence-related services (such as air raid welfare badges). The old gold colour of this ambulance service badge does have some similarity to wartime-produced items.
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