Manufactured about 1921-22, from the serial number. The stocks look great. Pity about the damage on the sideplate and other spots, but you can get most of the rust off by soaking it in a good penetrating oil (Kroil, Breakfree, Corrosion-X) for a couple of days and rubbing it off with superfine bronze wool or just a good piece of cloth. Then keep it oiled and clean, and it shouldn't get any worse.
I don't know if you have shot this, but .32-20s are great fun -- a very zippy .32 load compared to the .32 Long.
I have a 1913 .32-20 with compromised cosmetics (the gun was renickeled over an incompletely buffed surface) that shoots like a dream. Pity the ammo is so expensive and challenging to reload.