Keep in mind I live in Canada and when I say that civvy Alpha's aren't warm enough for serious cold I'm talking about well below freezing and serious wind chill. I'm pretty sure they'd be fine in the UK, and in fact the vintage/repro ones with the accurate wool/cotton padding would probably be too warm for most of the UK unless you're schlepping around in the Scottish highlands. I'm pretty sure BN1966 will broadly agree with me on that. Horses for courses. The polyfill civvy jackets have their place and for most people in most climates they're probably the more versatile choice as long as one isn't too fixated on historical accuracy. The shell on my USA made ~1990s civvy N3B is the same weight as the shell on the 1950s Albert Turner N3B that I had for a while, it's only the insulation which was different. It's hard to pin down dates with some of this stuff unless one is a total "tag queen" since all versions of the mil-specs aren't easily available (usually only the most recent document is available).