I remember in my dim and distant past, a time when the 'discerning' among us had our No 1 uniform jacket modified by having a 'bespoke' tailor shorten the jacket to the waist, replace the front buttons with a zip, add rank, brevet and medal ribbons and a luridly coloured silk lining et voila!!
This produced the best, probably the smartest and certainly most comfortable working, everyday jacket ever!!
I don't know or care how legal it was but quite a few of us had one. Much better than the 'bomber' jacket.
Unfortunately, after many years' of loyal service the silk lining wore through and I couldn't afford a new No 1 uniform to replace it.