allright, firstly excuse me for my english
i do not know english measurements and the names of some tools i used
But for MDF i went to the local do it yourself store where i bought 1 sheet of mdf 600 x 1200 mm , 4 mm thick
its around 5 euro's
then i meassured my display screen and added 9 mm on all the sides.
When i cutted it out i glued some support wood wich i made 5 mm angled


backside
then with some trial and error i meassured the insides and took a piece of mdf with some over overlenght above the bezel
then i secured it with 2 little nails so i can trace the shape of the monitor on that small piece of mdf

to get a good result at the corners use this piece tfor a new one because its kinda difficult to get good meassurements from the top of the bezel to the monitor screen.

then i sanded everything smooth and rounded the sharp edges.

now ii am ready to fill any unwanted cracks and small errors, sand it again and paint it black
hope this info will help all to get the same cool result as i have