SY, it’s interesting you mention the Benelli 750 Sei, which to my knowledge was the world’s first series production six-cylinder bike when released in 1972. It ruled the six-pot roost until 1978 when Honda released its iconic CBX 1000. The Honda not only had larger displacement than the Benelli but it had double servings of almost everything else – DOHC vs SOHC, 24 valves vs 12 valves, six carbs vs three carbs etc. However, I reckon the 750 Sei’s three-into-three exhausts looked more spectacular than Honda’s three-into-one arrangement. And it beat Honda to market by (appropriately) six years!