Summary

Some odd early-mark Spitfires, tailored for the FDM printer.
The Spitfire Mk VA was developed as a stopgap fighter in early 1941. The aircraft was simply a Spitfire Mk IA with a Rolls Merlin 45 engine in place of the Merlin III V-12. Around 94 late-production Spitfire IAs had been fitted with the new engine in the factory, with another 83 IAs and 52 IIAs modified as such for a total of 229 aircraft.

Spitfire Mk III prototype N3297 started life as a mid-production IA. Halfway down the production line, she was fitted with a Rolls Merlin 20 engine. The new powerplant also resulted in a larger radiator and a new oil cooler. A cut-down set of wings was also fitted, as well as a retractable tailwheel. Trials with this setup proved quite a disappointment, with some criticizing the longer landing run caused by the clipped wings. The Merlin 20 engine was also expensive and demanding to maintain. By May 1941, N3297 traded her original wings for a set of full-span wings. She was then given to Supermarine, which then tested the Merlin 61 engine with her. She became the prototype for the Spitfire Mk IX, the RAF's fighter mainstay for the rest of the war.

Another Spitfire III prototype was W3237. Interestingly, she had received her Merlin 20 engine in early 1941, well after the program had been canceled. However, that was it. She still had the full wings and the fixed tailwheel of a Spitfire Mk V, which she originally was. An A-type armament of eight .303-caliber machine guns was fitted, and she was sent off to the USA for further testing.

As a bonus model, I've fixed a key issue with the original Spitfire IA/IIA model. The model had a problem with the two outermost gunports. I've included the model here if you wish to replace your old ones.