The wedge top bar is most used with wax foundation, either with the wires or without. Break the wedge strip out and place your foundation in that space. Then, nail the wedge strip back on top of the foundation (not too tight, but snug enough to hold it), and you are good to go!
Frame replacement parts are #1 grade.
Picture order from top to bottom- Grooved Top Bar, Wedge Top Bar, Grooved Bottom Bar, Slotted Bottom Bar, Hive End Bar, Medium End Bar, Shallow End Bar