My Putnam book on German ww1 planes is a rather dated 1970 edition and shows earlier Gigants with 3 engines having gun positions in front or in the rear of the actual nacelle itself, depending on whether the version had pusher or tractor props. If you can check and confirm whether the R VI with its combined pusher and tractor nacelles had these rather draughty gun positions, poking out of the wings, that'd be helpful. They don't show in the photos or drawings in the book but as I say it's quite an old edition.
Re files, the chap who did the .dat file extractor for Mafia has looked at this and reckons the files have changed and that his tool won't work. We've so far found a payware one that extracts but the trial version only does 30 files a go. However, we're hopeful that when a dev forum comes online, or the "unofficial" Czech one, we can make some headway with Silver Wish, or otherwise make further progress.
When you soar into the air in a Sopwith scout And you're scrapping with a Hun and your gun cuts out Well, you stuff down your nose till your plugs fall out 'Cos you haven't got a hope in the morning!