Yeah I have the same problem so it's not just you. Snes downloads as super famicom for me, but I'm in England so actually want that console design bust snes branded. Also again cause I'm in England I want sega megadrive not sega genesis, my platform is named sega megadrive, launchbox says its downloading megadrive video, but I end up with the genesis one. Also I have the turbografx problem as well, I have tried NEC TurboGrafx 16, Nec TurboGrafx-16, TurboGrafx 16, and TurboGrafx-16 and it has never downloaded for me. I am using all default launchbox system names except megadrive which I scraped as genesis then renamed. I did mention about having a list to @Jason Carr on one of the live streams so we could cross reference what we have with what is available but I don't think he has posted one anywhere, he did say in the stream though that there is a turbografx video. So I have no idea how that is named on the server.
Sorry I could not help you, but just wanted to say that you are not alone with this issue.