Here is a photo of the home-made forward catapult fittings. The sling would be hooked to each of these and then into the shuttle in the carrier deck catapult track.
March Group Build> Spitfire and Seafire
Then, finishing the cockpit insert and shoulder harness.
March Group Build> Spitfire and Seafire
And assembly of the wing and fuselage. The red filler you see is about all that was needed on the entire kit.
March Group Build> Spitfire and Seafire
March Group Build> Spitfire and Seafire