Crashed Spitfire photo identification No.611 Sqd

[VoyTech]

Alex, I referred to the Mk II you mentioned. At the time when 'A' and 'B' were still used alternatively on consecutive aircraft there was no rule saying "'A' on even serials, 'B' on odd serials". In some Mk I/Mk II batches 'A' scheme was applied to aircraft with even serials, in other batches it was 'B' scheme on even serials. To know what scheme was applied to a particular early Mk I/II you need to know the rule that applied to that particular batch.
After 'B' scheme was dropped altogether it became immaterial whether the serial was even or odd - it was always 'A' scheme.