Early Mustangs (Allison-engined) - Aluminium Lacquer
	Wartime Mustangs (most of them!) - bare aluminium roof with yellow zinc chromate spar at rear
	Late P-51D and P-51K, and subsequent variants - overall yellow zinc chromate

Mustang wings were 'semi-laminar flow', and as such, surface condition was critical.  To this end, all joints and seams in the wings - upper an lower surfaces - with the exception of access panel edges were puttied and smoothed at the factory. The 'unputtied' panels were the ammunition/gun access bays on the uppersurface and the fuel tank access panels on the undersurface.  This means that the wings on 'natural metal' Mustangs were painted in silver lacquer.

Undercarriage Doors

	The wheel cover doors (known as the 'D-doors') on all Mustangs opened as the undercarriage was extended, and the closed again to maintain a smooth airflow .
	On Allison-engined Mustangs, the doors were mechanically latched shut, and so should be modelled in the closed position unless depicting a servicing situation.
	On Merlin-engined Mustangs, the doors were held shut by hydraulic pressure.  As the pressure bled off, the doors drooped open, often asymmetrically.  On a well-maintained aircraft the process could take several hours.

From left to right : P-51 with doors fully closed,;P-51D with doors starting to droop; P-51K with doors fully open.

Cockpit Colours

	Interior structure & cockpit walls - Interior Green
	Metal seat & cockpit coaming - Dark Dull Green
	Instrument panel & Control Column handgrip- Semi-Gloss Black
	Floor - Black (Merlin-engined aircraft) or dull aluminium (Allison-engined aircraft)
	Straps & Harness - natural webbing or khaki drab.

Mustang cockpits - the first two (at least) are restorations, but the right hand picture is believed to be original.

Undercarriage Angles

A frequently seen mistake in Mustang models is to fasten the main undercarriage legs at right angles to the fuselage datum, so that they hang straight down.  To avoid the 'tippy-toed' look that results, make sure that you rake the legs forward - by 11°.

The forward rake of the undercarriage legs can be seen here.

Weathering

Look AT PHOTOGRAPHs!     There is no substitute for a good photograph of your subject aircraft.  In the absence of such evidence, however, there are some guidelines to follow:

Mustangs of the 8th Air Force led a relatively sheltered life.  They generally returned to permanent bases outside the combat zone,, where their groundcrews could tend to them before the next mission.  Accordingly, weathering on 8th AF P-51's is slight.  Exhaust staining is seldom heavy, although heat damage to early Olive Drab paintwork is often obvious.  It is rare to see much staining around gun muzzles or ejector ports.  Staining - such as it is - is more common on camouflaged airframes than on unpainted ones because the stains were harder to remove from matt paint!  The RR Merlin had a tendency to spew oil liberally from the engine breather.  On the Spitfire, for example, this oil leaked and oozed through the joints in the bottom of the engine bay, giving the Spitfire its characteristically streaky belly.  North American's engineers led the breather tube to a vent on the lower starboard nose, leading to a much neater single plume of excess oil down the P-51's right flank.

The 20th FG aircraft on the left, and the Michigan ANG aircraft on the right show the characteristic oil plume.

 

Aircraft flying with the tactical air forces (eg. 5th AF, 9th AF, 10th AF, etc) were much more likely to show the effect and depredations of combat.  Their bases tended to be more primitive, facilities for repair and maintenance more limited and enemy action more likely than was the case with the strategic air forces.  As a result, airframe titivation at turnaround was often limited to a cleaning of the canopy.  It is also well to remember that Olive Drab paint was notorious for fading, staining and bleaching.

Well weathered Mustangs of the 1st Air Commando, US 10th AAF.

You can find lots of Mustang photographs on-line, but beware - most of the clear glossy pictures are of restorations, and as such are a very poor reference source for modelling - particularly of weathering!  Worth a try is :

    http://www.littlefriends.co.uk/  : The webpage of the 8th AF Fighter Command Association