Got down to this line in your install instructions
sudo scons udev-instal
But it stopped with this:
WARNING: gpsplot is missing required runtime module matplotlib
WARNING: Python2.7 too old (need 3.6): gps/aiogps.py will not be installed
Ensure your PYTHONPATH includes /usr/local/lib/python2.7/dist-packages/
Python 3.6 is currently installed.? I can't find matplotlib to install.? Can you help me furher?