As an addendum to my prior answer, I would add that I would take Spitfire Mk XIVs over any American fighter or most other British fighters from 1944/45 for use as a Spitfire Mk I replacement in the Battle of Britain. Climb rate, speed and firepower. The Spitfire XIV brings it all.
I do think the Mosquito Mk VI/XIII, XIX or 30 would have been even better though. Just think of the poor, helpless German bombers against a fighter with four cannon in the belly and too fast for a Bf109E-4 or E-7 to hope to catch. Not to forget a fighter than seriously hurts the German's ability to gain protection by switching to night raids.