Don't sell it. Stevens 311s in 12ga only go for 2-300 dollars, but the .410s go for 6-800.
I'd hold on to it. Sure, it's a utility gun and not a classic, but it's not often you can have a utility gun that is worth 600-800 bucks.
And a good little utility gun it is, too. I had a 311A that I killed a boxcar load of small game with, and about half again as many quail and doves. I think I gave 85 dollars for it NIB.
It patterned well with all shot sizes except #4 and it shot where it looked with both barrels.
It even shot 3 inches high and converged at 50 yards with slugs. I couldn't have asked for more in a 2-shoot scattergun at any price. I've since had a half-dozen...sadly no longer around...in 12...16...and 20 gauge, and the performance was excellent with all. Never had a .410 but I'd seek one out if I was still into upland hunting.
My personal favorite was the little 20 gauge with modified and IC chokes. That was a bird killin' piece of plunder and I've regretted giving it to my nephew since the day it went home with him.