Are you missing any equipment? All optional equipment such as AC, Sand filter, pop-out floats etc can be retrofitted.
Push-out windows
Tinted cockpit skylight panels
MARMS aircraft monitoring
Auxiliary Fuel Tank - fixed provisions
Enlarged footstep installation (LH & RH)
Cargo Hook - 3.8 tons fixed provisions
First kits I torches
4 Ax.is - Autopilot
Dual controls
Pressure refueling system
Engine intake anti-ice protection
Fixed and controllable landing lights
Heated Windshields
HUMS
Additional mirrors - cockpit door (LH&RH)
Emergency Flotation System - 4 bags
Single Hoist Fixed Provisions
Deployable ELT - HR Smith
4 point passenger hamesses
Solid State CVFDR - AR 204C
Reinforced cabin floor with fixed covering
Active Vibration Control
HEEL