.If HEMTTs were rare war artifacts (like, say the lend-lease Studebaker trucks), and you had hacked one up you might get some grief from somebody here.
As it is, I think you took (part of) something common that's mostly impractical for civilian use and made something cool and interesting out of it. Excellent fab and finish work, and I hope you enjoy using it as much as you enjoyed the project of building it.
It looks, incidentally, like it belongs in movies. Be sure the studios know it exists, as they've paid good money for use of things like it over the years.
Before recently, I wouldn't have thought big green trucks would be all that interesting that the movie people steelypip . However, I have seen several calls posted here for trucks. All of them have been on the other side of the country - but there are definitely opportunities!
We have had several small movie productions in the giant warehouse beside our printshop. It seems that it all depends on WHO you talk to on the production. We have printed a lot of prop materials for the things that have been shot in our little corner of the world. The last film we supported was a military (made for television) movie. They folks I work with were thrilled when they saw some of the toys that I have here but nothing ever came of it during this latest version. One of the propmasters dragged one of the directors over late one afternoon - and we might be in the next shoot... I personally can't wait to see one of my babies in a "movin picture" .