How old is LeFever Arms Co Ithaca NY Nitro Special 28 double barrel shotgun with ducks engraved on the side sn112742. What is it worth?

I can say that the LeFever Nitro Special was made from 1921-1948.I do not know if the serial numbers by year of production are available in the public domain.You may have the Grade A field model due to the engraved ducks on the side.These were made from 1934-1942.Barrel length was available from 26in.-32in,of which your shotgun fits.