Nice find. Don't often find Nitro Specials in that nice a shape!! According to the table in Walter's book that is a 1936-vintage gun. From the Jan. 25, 1936, Dealers Quotations a Nitro Special had an Advertised Retail price of $28.90 and the single trigger was a $4.60 option. There has been a 20-gauge Ithaca-built Lefever A-Grade Model 5 with the single trigger sitting at a shop near me for some time now. It also has a rather short stock and a recoil pad.