The 1926 price list shown on page 69 of Walt's book offers a recoil pad for an extra $5.00 retail, but it is not the "Bridge Trestle" pad. The "Bridge Trestle" pad isn't mentioned in any of my Ithaca catalogues up through 1931-32, but it is prominantly displayed from 1932 onward. On page 76 Walt shows a 1931 price list that states "Ithaca Standard Recoil Pad on any gun except Field Special $1.50 price to dealer, $2.00 suggested retail. There is a double plus sign after those prices and in the footnote it says "Recoil Pad price reduced from $5.00 to $2.00 retail. The order blanks in the early NID period catalogues shows a gun with a Jostam Anti-Flinch recoil pad. By 1935/6 time frame they cropped the picture not to show that Jostam pad any more.
