(later, the P1127 was followed by the Kestrel in 1963-1964, the concept further being developed, resulting in the later Hawker Siddeley Harrier)
See references...
 

Although in Dutch, the article presents many drawings and a lot of models made by Bas. And my friend Bas still had a couple of old Airfix kits, so I got a P1127 kit from him to build. The box is seen here: 

The kit was originally issued in a bag, seen right.

The model
The Airfix P1127 model from 1963 is very very basic, being more than 50 years old. The rivets were sanded off and the surfaces made smooth even before gleuing the first part.
It has few optional parts such as 2 noses and 2 different rear exhaust pipes (parts 22 / 23 etc). But during testing, various intake configurations were tested, so when you want to make a certain type, carefully study pictures. The first prototype XP831 had bulged inlets (NOT in the kit) only for the hover test flights and was fitted the thinner inlets for normal flight as in the Airfix kit. Also the XP836 has these later style intakes. 

        left: thin intakes,  on the right the "bulged" intake

(The kit includes parts for the round nose of the later Kestrel and a rounded tailend. Please note that the later "Kestrel" Harrier can not be made of this kit as the fuselage is much fatter, more like a first Harrier GR.1).

The parts... There are a lot of shrink marks and scratches on some parts to be cleaned up. 

One outrigger wheel strut was missing, will make one from a spare of another Harrier kit. 
The kit intakes with engine fan are very basic. It represents the intake without any blown bulged intake floats. It picked the P1127 with serial XP836 of the second prototype for this model, which has the intake as in the kit. 

The canopy is far too wide, it needs replacement. 

Assembly
From card an aerodynamic fairing towards the "pegasus" engine fan was added inside the intake, gaps were closed with with glue. 

The engine nozzles were simply fixed and glued in place in each fuselage half.
Next, the engine fan was inserted and the fuselage halves joined.
Also, the main wheel undercarriage bay was cut out as well as a part of the nose wheel bay to give these depth. 

The cockpit is almost non-existant, so a floor and rear bulkhead were added from plastic card. The canopy is one piece but clear enough (will be fitted later). 
Please note the gap in the forward fuselage deliberately kept to get a better fit with the nose cone.

Next came the wing halves, they also need lots of sanding and filler to get a smooth joint. For the XP836  the inner flaps gaps were closed with plastic card

The fit of the fuselage halves was not very good, particularly at the lower side filler was needed. This is caused by the very worn mould. Also the nose cone needed filler and a lot of sanding to get a smooth look. But the results are worth it and is quite quickly accomplished on this small model.

The rear jet exhaust part 23 for the P1127 was replaced by an open piece of a straw of right diameter.

The model now got a base coat of grey with the airbrush. Some flaws were seen, and some filler and sanding needed in places.

Still some more filling and sanding is required...
 

After sanding, another base grey primer coat was airbrushed on. Next, the model got a coat of aluminium. I decided not to do a fully shiny coat, but a normal aluminium coat using ALCLAD II aluminium no. ALC101

Time now for the markings, which are simple and basic. First, the model got far better roundels for the period using Xtradecal set. The serials could be replaced with, a co-incidence, decals spares the spare decal box (probably of a Jaguar?).

Some black painted details on the airframe were now hand painted.

The undercarriage, outrigger wheels and nose wheel strut and wheel were added. The nose wheel doors were made from plastic card and painted as well. 
 

The forward "cold air" swivelling nozzles were painted gunmetal, the rear "hot air" nozzles burned metal.

The cockpit is very basic. With some card, an instrument panel and side panels were added. 
 

The cockpit was not painted overall black although I am  unsure about the interior colour, I kept it plain metal with black details. The ejector seat came also from the spares box and painted with add straps from tape an cut decal lines. Some instrument decals came from the decals spares box. 

The canopy is far too wide. I found a spare rear canopy in my spares box of an old  Italeri 1/72 Harrier. But I found no windscreen but discovered that a Skyhawk windshield can be used found in the spares box. The windschield was set into position, closing tiny gaps with white glue. The rear canopy was set open and the rear open lower area blanked off with a thin sheet of aluminium.

That completed this nice little model of the Harrier pre-decessor...... the P 1127

Note the retained "kit" riveting

 note the details in the small cockpit 

A nice little gem in the 1/72 British prototype model collection!
 

- old nostalgic  Profile 198

- Harrier in action, no. 58, Squadron Signal publications, USA

Also check out Internet: 
http://en.wikipedia.org/wiki/Hawker_Siddeley_P.1127 

With my good old friend Bas (in 1995 , what seems decades ago) I made an extensive article for the Dutch www.ipms.nl about the Harriers and AV-8. Check out the article that is now a "special" on the IPMS NL website at: 

https://www.ipms.nl/artikelen/specials/harrier