Click to enlarge images
Here is a Spitfire HF Mk. VII undergoing tests at NACA Langley in the United States. Both photographs have been taken on in July 1944. The aircraft is EN474, 13th production high-altitude Mk. VII which was supplied to USA for evaluation. The same Spitfire was previously shown here.
Interestingly, the aircraft apparently flew without the undercarriage covers at this point.
EN474 survived the war as is presented today in the collection of Smithsonian National Air & Space Museum in Washington DC. [NASA]