Some years ago, in Southampton's Hall of Aviation, I saw an aircooled flat-6 on display with a Rolls-Royce badge/logo on it (maybe it's still there). I remember it because I thought at the time how neatly it would appear to fit in the back of a 911, and what a unique combination it would be.
I have not come across any mention of it in print either before or since - was it a literal case of badge-engineering, or maybe somehow connected with those already mentioned?