Rick,
For what it's worth, (very little) at one time I worked for the paint company that for many years supplied almost every machine tool manufacturer in Britain.
I can assure you that the formulation was not 'nothing more than an air drying brushing enamel'. It was indeed air drying but most companies used what was termed conventional spray. A lot of work had gone into achieving a level of oil resistance, hardness and the high gloss which was preferred. It was sold as a 'system' of primer, filler and top-coat.
That company would match any colour which was asked for. I suggest you should forget any connection with RAL colours (German standard) and concentrate on BS 381. No self respecting British company would use anything other than British Standards. RAL in the UK is 'Johnnie come lately'. It was only with the influx of foreign electronics companies that RAL gained a foothold.
Unfortunately that well known paint company fell apart some years ago and was taken over by the Germans. It is still operating in the UK but what happened to the formulations? I don't know.
Jerry