The Greener is a very fine shotgun, and if taken care of, and not loaded up with super hot stuff, will last for generations.
A friend of mine, who is in his 70s, was handed down one as a boy from his father, and his son, in his 40s, is shooting it today.
Market hunters and goose hunters used 10 gauges, and later, about the 1920s, 3 inch magnum 12 gauges like the Ithaca, with 32-inch barrels, full & full ( which shoots a very tight pattern with #2 lead ).
The Greener is in the class with Parker, but most are a bit lighter in the barrels. Yours looks in great condition. A gentle restoration would do wonders, without taking it all apart. If the finish is worn through, the stock can be gently stripped in place if it has no oil softening around the action, using some lacquer thinner. These older guns were often lacquered, before the invention of varnish. Some have boiled linseed oil finishes. You can figure a lot out when you remove the recoil pad. Old shotguns which have gone grey and shiny, I just strip with bluing / rust remover and reblue, by rust process, hot ( warm ) bath, or Brownell's Oxy in multiple passes.
I am getting ready to restore an old Ithaca next.
There is a gunsmith in Tennessee who does rust bluing, and will do the entire thing pretty cheaply, if you want to go all the way.