According to the Kagero book about the Wildcat the interior of the fuselage was painted with Zinc Chromate Primer FS33481.
"F4F-3 / F4F-4, Wildcat. Cockpit: FS 34058 Bronze Green. Some may have been painted FS 34151. The inside of the engine cowling and main gear bay were Light Gray, as was the interior of the fuselage all the way back to the tail. Tri-color aircraft would have had Insignia White wheel bays (cutout for the tire). The only area that was Bronze Green was the pilot's portion of the cockpit above the 'Floor'. The fuel tank under the cockpit was light gray or black with an interior green supporting structure. The area below the floor was Interior Green.
FM-1 / FM-2 Wildcat. Cockpit: Interior FS 34151, Interior Green. Similar to the TBM. Wheel bay (cutout for the tire) was the exterior color. The engine accessory area (the area behind the firewall) was Light Gray. Tri-color FM-1's likely had Light Gray engine cowling interiors and the rear fuselage was Light Gray also."
"However, on 21 December 1942 the Chief of BuAer wrote to the Naval Aircraft Factory clarifying the correct hue of Zinc Chromate to be used. In this he stated that it had been agreed by the Army Air Force to adopt the "Navy cockpit green" as the "standard" colour for tinted Zinc Chromate primer and that it had also been agreed to change the name to Interior Green."
I would suggest using the Model Master Dark Green FS 34079 which is close to the Bronze Green.