The 'LLH' is the mark of
Laurent Lochet-Habran, a Belgian barrel maker who supplied the 'rough forged tube' to many U.S. makers. This mark has been found on Fox, Baker, Lefever, Crescent, Ithaca (Flues, NID, Lefever Nitro Special, and Westernfield Deluxe/Western Arms Long Range), Hunter Arms Fulton and "Ranger" for Sears guns.
If it's a Nitro Special it was made in Ithaca, by Ithaca Gun Co. The serial number does not fit the Lefever Arms Co. numbers, and if a Nitro Special should be 1928
http://www.ithacagun.com/pdfs/serialnumbers.pdf 
