It tends to be a bit tail heavy, so you'll want to add plenty of nose down trim (num pad home key) right away.
It has a cockpit, and gun stations borrowed from Christophe Rosenmann's B29S, waist guns from the stock B25, and a bombardier station from Edward Cook's Whitley. None of them are really correct, but they are in about the right locations to match the G4M1 model. You should toggle F3 to hide the offending gun station objects from your view. Other than the tail gun none of the sights train along with the gun movement for some reason so you'll just have to shoot by hosing tracers around.
Published with permission from Stephan Saybolt. Unfortunately his original source files have been lost in a hard drive crash, so this is about as good as it's going to get unless someone can create real cockpit / gun stations for it.