The article on building custom radiator covers in the November issue overlooks one critical issue. This design, with an open front and  solid shelf on top of the radiator will reduce heat output by about 15%. A preferable design will have the screen on top, and a solid front, to create a stack effect, improving airflow around the radiator and aiding convection. See the attached article at HeatingHelp.com for more detail and the D.O.E. study on this subject.
https://heatinghelp.com/systems-help-center/radiator-covers/
I spent good money to have similar covers made, only to find I was then wasting fuel dollars!
Mark