That sounds like a fun experiment, let me know if any of your players survive.
I am writing an adventure for Shadows of Esteren myself currently.
its set right when the characters are all young and doing their military service. The new recruits get sent into a nearby spooky forest to investigate strange lights and then get jumped by Feondas
Other than that, I have run 'Night of Fright' from Book 2, 'The Poisoning' from book 0 and just finished up 'Loch Varn.'
i've replaced the Feondas in each with my own creations.
I am not as good an artist as yourself, but I could post some sketches if you like?