My printer (used) did not have any LCD mounting when I purchased it. so after a few failed attempts this is what i came up with. I used the Original Prusa MK2 LCD_SupportA and B to make the screen Supports and i used Filament guide by Clivebradshaw to make the frame clip. once printed it will seem to not fit the frame or you may crack it. i recommend using a scraper or something similar to help ease the bottom around the frame, as this seems to alleviate installation issues  

i printed this with Prusament orange PETG .3 layer height at 20% infill 3 perimeters and 3 top and bottom layers.