Smith Wesson never made an I bolt rifle Thier bolt action rifles were the A 1969 to 72 Model B same vintage with Schnable foreend Model C added the cheek piece D was a full length stock and E Full length stock with No cheek piece. These rifles were made for Smith Wesson by Husqvarna of Sweeden . The Model 1500 1600 and 1700 series were made by HOWA of Japan which ceased production in 1984. Mossberg bought up the remaining parts and made the rifles until 1986.
So depending on when you gun was made its either a Husquvarna , Howa or Mossberg parts gun. A refle scope mount form either of those companies gun should work