Updated 4 June 2019 - Fixed the centering issue within +-0.003mm (photo still shows slightly off center part). Added .f3d (Fusion360) and .step format files of the latest version for remixing.
Fit an Adafruit 3.5" TFT LCD touchscreen Octopi rig in the front panel of the Prusa i3 Mk3, keeping it centered on the printer frame, with no other modifications to the printer. That was the goal of this project, and here's the result. Based on the Prusa LCD Super Cover by yetisnack for Prusa i3 mk2/mk2s. This cover is tilted back about 25 degrees when compared to the original Prusa cover, in order to accommodate the extra bulk of the rPi + TFT display and associated cables without interfering with the build plate. It includes built-in legs to mount it to the printer. Taller rubber feet for the printer are not necessary.
Easy to print in PLA with optional supports on the build plate. With a 0.6mm nozzle and 2mm layers, it prints in just a few hours.
Reuses the existing hardware for the front panel to mount the Prusa LCD to the cover, and to mount the cover to the printer.
For mounting the Raspberry Pi, I used brass inserts threaded for M2 x 2mm hex bolts. Be very careful mounting the touchscreen; it's a tight fit and if you force it you will crack the screen. The USB port to power the Pi is accessible from the bottom, but you may want to use a 90 degree cable to minimize any force on the USB port.
Depending on your printer, support may not be strictly necessary. Only a small amount of support is required, so it's worth it for the peace of mind.