In the 1940s no one bothered at all. My dads home guard 303 sat in the porch for years. Airguns were classed as toys you could "open carry" one in the streets or down to the canal bank.

I had a Diana "chuck out" circa 1963 which came with the coloured tufted darts, I thought it the best thing since sliced bread (if we had sliced bread back then.) 

we used .177 Milbro pellets, cat slugs were a rarity but we bought them when available as they were just as much fun and were cheaper they also made a nice ricochet noise when they bounced off a hard target