The most interesting part of the article, for me, was how Max Fritz reverse engineered a surplus WWI Douglas boxer-twin engine in order to create the BMW R32. The 2-wheel drive R75 military model eventually evolved from this model, and it was considered so superior that many other nations sought to replicate it. These models included the Ural Dnepr M-72, the Chang Jiang CJ750, the Harley-Davidson XA, and even the Indian 841, which as we know had a longitudinal V-twin engine like the Guzzi.