Side note: galileo is going to sell things to use satellite and they plan to broadcast some of the patriot voices over ham radio. In U.S. we can access ham radio through the internet.

UK CB started in 1981 with 40 FM channels. The UK has a relatively small area so it wasn't long before all channels were swamped by people, mostly talking drivel. And, because it's FM, the strongest signal wins. Unlike AM you can't hear two people at the same time. Getting in "on the side" is harder. And there's zero privacy.

The channels were full of "muppets" bent on destroying conversations. After very few years, most people gave up and this was accelerated by the advent of mobile phones, which offered privacy, distance and ease of use. 14 used to be the calling channel and 19 the mobile channel. 9 was intended for emergency use only. But it soon became a free-for-all.

Nowadays there are relatively few users so it's usually possible to find an unused channel. Also, I believe that it's possible to use 80 channels legally.

The original bank of 40 channels goes up in 10 kHz steps to 27.995 MHz if I recall correctly. The newer band matches the original "FCC" band but uses FM. (I'm not sure whether AM and/or sideband use is still prohibited. I know they are used in some European countries.)

As I no longer reside in the UK, I can't answer the OP's specific questions except to say that a dedicated WWG1WGA CB channel is unlikely to exist. Also, since London suffered the Coudenhove Kalergi invasion, English isn't the only language spoken.

Some friends and I created a "private" CB channel by switching up the ch40 frequency to just above 28.000 MHz. This was illegal but with such a short range and so much general interference, we never got caught!

I don't know much about amateur radio except that the Morse test was dropped and obviously lower frequencies travel longer distances.

Most CB/HAM portables transmit at 4 watts which is good for local repeaters and CB comms for 1-3 miles.

Until 1981 CB's were illegal to own or operate in the Uk and when I was there in 2009 CB wasn't a thing in the Midland's I visited at the time.

Getting regular comm's from the Uk via HAM is possible...provided the location of the transmitter the quality and the height of the antenna and the condition of the atmosphere and the property's of HAM freq's being used.

Anyways possible but given the list of conditions the people you will be able to contact would be few but a blast none the less. Considering the Ofcom license process, not many regular people apply unless they have a large budget and business reasons to have a the larger more powerful HAM radio base stations.

I'm not the last word as I test for my HAM Technicians License next Monday, still new to all.