Actually, this isn't "untested territory", there's been maybe four or five WWII RPGs. All of them failed. Then again, the NSWRPG forum has a long trail of games that died in their malformed infancy. If you want to surpass that legacy, you're going to need a small group of players that are as crazy as you are. You need to capture their interest and convince them that you have something they want to read about and play. Of course, opinions on how to do that vary, and if we all knew how to do it we'd probably have a lot fewer games in early graves. Really, about the only thing you have any control over is the amount of effort you put into this. So put on a show. Open with an in-character briefing from the higher-ups for the first mission using some maps of where they're going and what they're doing, or some sort of bulletin or broadcast, maybe start in a prison yard with the command sorting through the list of prisoners and have the players describe their characters in the words of another character and explain what they bring to the table. You don't even necessarily have to have your opening scene be the first one the players are in, you could start with a plane over enemy territory and then flashback or something, really the possibilities are endless. The important part is you want your game to jump out and inspire your readers and potential players. You've got something, but why not make it into something more?