As an example, so many times it is noted in ads, stating "factory period pad", when in most cases the factories NEVER installed pads but left that option up to dealers and hardware store smiths on pre WWII guns.
I don't know what percentage of pre-WWII American doubles left the factories with recoil pads, but my 1940 Shooters Bible does show recoil pads as a factory option on Parker, Smith, Fox, and Iver Johnson doubles. Interestingly, the only double I find on which a pad was factory standard equipment is the Stevens 530.
On foreign shotguns, if choke isn't marked, you'll have difficulty determining what the original constriction was even if you can access records. I owned a pair of Army & Navy 12 bores on which I had the complete records. No indication of choke. And when the barrel on a Brit double says "choke", all that tells you is that the gun came from the factory with some constriction--but maybe as little as .004.
