This simple supporting structure is designed to hold the MIP at the correct height and angle. The supporting braces have been placed externally to allow a clean interior finish ready for all the cockpit item to be installed.
Here you find the basic dimensions to produce a perfect fitting sim. They are super simple to create, being constructed from 18mm MDF. There are a few angles to get right, but nothing too taxing. These fit exactly to the sidewalls and sidewindows here at www.737DIYSIM.com. They also help support the overhead structure if you decide to build that far.