Thanks for the welcome and understanding UKblonde and christopher.hulsey. I decided to book an appointment with a GP today, but was told the same story I was given a few years ago when I asked my GP for a prescription of antabuse.
I'm told that substance abuse / anti-addiction medications are off the menu in my local area. GP's will only refer you as an outpatient to a local drug addiction
charity 
, and cannot hand out prescriptions for these meds.
When I called up this 'charity' I was told they were offering meet-ups once a week for tea, biscuits, and a group chat, with a possibility of a 1-on-1 chat session with someone from their organisation about once every 6 weeks, and was given the impression that this was a very weird enquiry i'd made. They also confirmed that they don't hand out prescriptions, they said only GP's can do that.

Would be funny if it wasn't so serious. AA suddenly looks pretty damn good compared to the NHS's handling of alcoholics in my area.
It's overseas purchases for Nal or nothing for me. Will just have to cough up the money and sit tight until they arrive. I'm at least pleased to hear the possibility of getting meds on prescription exists elsewhere in the UK. Postcode AND GP lottery ey?

Person I had to see to obtain NHS prescription was/is the prescribing Dr for the local NHS team, have you tried googling NHS drug and alcohol team in your area?It's confusing these days because of the different charities and NHS calling themselves various names.
If you remember I also went to my GP already having started TSM via private prescription from Dr C, prior to that she wasn't interested in getting involved - so I don't think it's as straightforward as postcodes. I do also know another reason GPs don't prescribe is because they simply get no experience of the stuff, because they farm it off to outside agencies(which is fair enough since they can't be experts on everything). This isn't an excuse just an explanation of the situation, and it is a complex issue we have too.