swing screen door frame extrusion

I have an old screen porch with the usual aluminum extrusions that accept the screen with a rubber spline. The swing door frame/jamb is made of a matching aluminum extrusion that has a recess or stop that the door closes into all around the door. 2" deep with 3/8" recess for door. It needs replacement. I am not finding this extrusion shape anywhere online or at big box stores. Can you help? What am I missing here?