Without breaching poly ticks .....
In 1973 the best known Single Action pistol probably on the planet was 100 years old and basically unchanged .

Arguably the best known and most copied rifle on the planet by 1973 was 75-85 yr old. The Gew 98 was only 75 but the very similar assorted 1891s through 1896s , type 38 etc were nearly 85 .

As far as cartridges go aside from bullet enhancements it's pretty hard to find serious flaws in any of them over 90 yr old .

The strongest production Single Action Revolver , cheapest but most likely to produce good results Rifle , and most villainized rifle ever produced, are 75 yr old next year .

Just saying.