[Wolfe'61]

Need to source an insert for the forend of a old Ranger (Marlin) 103-11 O/U shotgun. The insert is knurled but non-threaded that allows the small machine screw to pass thru and hold forend stock to the forend iron (snap on type). Attached is picture of the insert, best I can measure the ID is 3/16" the OD of knurling appears to 3/8" and about 1/4" deep. Also note it has a stepped area that the machine screw pushes against for the holding tension. Have searched everything I can think of online (McMaster-Carr.....Numrich, Brownells, Grainger, woodworking supply sites......), and not coming up with anything close.... Looking for a little help, appreciate any suggestions.
Thks,