There was some talk on the Airheads mail list about the following bikes, and I had some pictures, so I thought I would share with you. Click on each picture for the full-sized version.
The following 3 pictures are of a Harley-Davidson XA, built for the Army during WWII and based loosely on a BMW made by (at the time!) the German enemy!
Below is a picture of an Indian 841, with opposed 45 degree cylinders, aligned perpendicular to the frame, like a Moto Guzzi:
The above pictures were taken at the "Miracle of America Museum" in Polson, Montana. This place is a cross between the Guggenheim and the Sanford & Son junkyard. Entry fee is only some $3.