This one might best be left to Moto Guzzi to work out as nothing so simple is ever so easy. Along with a high mount fender you would need lower fork tube protectors and new brake lines. There is a small under shield on the lower triple and if you had a stack of fenders in your shop, no doubt one could be cut and drilled to fit. The brake line T would need to be moved and new lines run to each side along with some wiring. In the end, given the far forward location of the radiator, I doubt you could fit much if any fender extending behind the steering stem. Really, just the opposite of what you would want for off-road work, more protection from mud and debris hitting the engine and cooling system and less concern for crud flying over the wind screen.
