The 1.19 inch measurement you have corresponds to the standard internal diameter for the slow-rise auto-stop position fixer designed to fit inside a 1-1/4 inch outside diameter aluminum shade tube, which is the correct size for your 2016 Tiffin Open Road 31SA dual shade. There is no need to modify or shrink a larger size part. The Irvine slow rise auto-stop position fixer available matches this specification perfectly and will fit your shade tube without alteration. You can confidently order this part to replace your broken slow-rise stopper.