Something that may affect the perception of what is and isn't appropriate is that, particularly with regard to shotguns, the British practise is to send guns back to the makers for periodic "refreshing".
This could be simply a clean, or a complete rebuild - and so it isn't uncommon to see guns in regular use that are 100-120 years old.
My usual bird gun was made in 1907, has been rebuilt once 25 years ago - and should be good for as long as the correct length cartridges are available, and pheasants are flying to shoot at. I hope the reference to modern guns is not inappropriate, as it was used as an illustration of how different approaches come to be.
I'd love the opportunity to shoot a deer with that rifle.