Ah the old starter button, now I notice that this is not all it seems in Guzzi world, when I got my 70 Ambo I noticed when researching on the web etc, that my bike never had one, I mentioned it over on my thread here... http://www.advrider.com/forums/showthread.php?t=841764
So I found and bought one from ebayland, and had intended to fit it at a later date. But, it would seem I had made a basic error, most of the info on the WWW, is from American sources, but my bike is an Italian home market bike, and as such has a few subtle differences, probably because they wanted to use up parts from older models.
My bike has a starter ignition switch, just like a car, turn it over and it starts
no push button needed, if you look closely you will also see other things, rear light, seat pattern, carb clamps.