Hello Matteo, here are a couple more Spitfire scans. first is the pressure relief valve on a Spit having an engine change. Second is a rudder frame being repaired. Fabric will be stretched over to finish it off. You can just see the little tag fitted to yours. Hope this helps, Ian.
Picture 8, item on the right with 30050 35 56 stamped on it is a Spitfire main undercarriage retraction jack trunnion. The jacks moved up and down slightly during retraction of the undercarriage and this trunnion allowed the ram eye-end to swivel.
I found recently as well the "ring"' on a crash site in Holland of a spitfire
Piece below the engine thermostat relief valve is the frame from a trim tab from one of the control surfaces - it is typical Spitfire construction - the small tab should have the drawing / part number on it.
thanks for sharing, some great finds