You beat me - I didn't buy my first shotgun until I was 17, bought it from the Littlewoods catalogue.
Yes, we all had airguns, and sheaf knives too. Airguns, shotguns, knives and cartridges were all available from the local ironmonger's shop, and from second-hand shops. We also bought airguns from other kids at school, which was allowed as long as they weren't loaded. One kid did go too far once though and brought a revolver into school, the teacher took it away from him and the headmaster wouldn't give it back and insisted that his father came into school to collect it.
Gun licences - yes, 10 bob from the post office, and no records were kept, it was just a tax, same as the dog licence. When I had to get a Shotgun Certificate for the first time (1986?) I just walked into my local police station, filled in the form and produced my driving licence as I.D. The desk Sgt looked me up and down, said "Any trouble with the police sir?) and when I said "No" he rubber-stamped the form, accepted my £10 , then signed the form and gave it to me. I still remember his advice "Best keep it under the bed sir, out of sight, that's where it needs to be if you ever have to use it at home". How times have changed!
I used to wear a sheaf knife when working on our farm, but it was always in the way, getting in and out of machines, so when those little "razor blade" locking knives became available I changed to those, much better for cutting string anyway. But the law isn't on my side. It's fine in the fields but as soon as I go into the yard I'm in a public place, and technically I'm breaking the law if I forget to take it out of my pocket, and of course that also applies if I still have it in my pocket (or in easy reach) if I go out in my car. Ridiculous, because it's impossible to work on a farm without a sharp knife, and some know-nothing once decided that locking knives are dangerous, the reality is that they are the only folding knives that can be used safely, so the law makes potential criminals of us all.
So, what's changed? Well, in this country I think that it's just a case of politicians who like to throw their weight around and create unnecessary laws, and as there were always very few crimes involving either guns or knives before they were strictly controlled, the changes to legislation do appear to be unnecessary. In the USA though, with so many extreme attitudes and a generally violent culture, they do seem to need strict laws but have virtually none.