Halifax Chair Paint Colours

I have started the restoration of a Halifax WOPS Chair. 

After stripping back the later white gloss it was painted black underneath and as this was directly on top of the anodized finish I assume it to be the original colour.

The chair was made by Rumbold and the plate on the base has a 571055C19 part number and an LAR inspectors stamp.

The main chair also has an inspectors stamp and matching serial number. The inspectors stamp is also LAR.

Is this the stamp for London Aircraft ( I had assumed it would be LAP)  ? for Rumbolds ? or for a 3rd party.

There appear to have been three variants of this chair.

1. Plain seat.

2. Later version with an armrest on the LHS ( from the AP)

3. The Hastings version with the headrest.

However there are also black leather/black paint versions of the first two as well as green leather/green paint versions.

My question is whether the colours were specific to the Halifax manufacturer – London Aircraft vs English Electric ?

FYI the white metal bearings that make the chair turn had seized and it has taken a lot of KROIL and Heat – but they have now been freed and the bearings are again turning.