Thanks for posting that link,
I’m not convinced that the references are for the same aircraft though, Reading between the lines seems to indicate that there were maybe two Spitfires in use.
II(AC) sent Mustangs to North Weald for gun harmonisation as there were no shooting in butts at Sawbridgeworth. It was while delivering those Mustangs that the Spitfire was found and then ‘liberated’ One or two weeks passed before being flown by S/L Houseman. That could have been the second flight mentioned. Apart from that, Dyce not being in the immediate neighbourhood either!