Are needed to house either the screen' frame, or a window frame.

Didn't have the router (electric) bit to make a 1/2" wide rebate, but, I remember I made a Traditional Chinese Edge Plane awhile back. Clamped the top rail onto the benchIMAG0191.jpg

Not sure what clamp that is. You can just make out the plane, hiding back there in the shavings it threw out. Rebate needed to be 3/16" deep. Better views?
IMAG0192.jpg
This was a skewed iron rebate plane. Need to add a depth stop...someday. For now, a #78 to clean things up. Looks like this when all done
IMAG0194.jpg
You are looking at a tenon. the angled part at the end of the rebate is the 45 degree detail. Goal was to go to the depth of the tenon. Rebate is square, too.

Top rail is done, three more rebates to cut.