Vertical and Horizontal lengths (from the 3D model: measurements at EIO and target-stick are compared with the real setup)
Total Vertical length = 56.20"
Total Horizontal length = 8.92"
References
1. https://www.cmrcet.ac.in/files/ECE/ececoursefile/19.pdf
2. http://miwv.com/images/Waveguide-Chart.pdf