That is a very early sandcast bike and motor and carbs. Very desireable and worth a lot of money to guys that restore them. You could sell the parts to the right sandcast guy and be able to afford several different bikes from the money you make. They go nuts for original sandcast stuff. It would be a shame to cut that bike up. But if that is all you have..no oem body work, tank, exhaust etc it will cost you a fortune to build it back to stock. I would get on a sandcast forum and see if someone want to buy it, you would get some good money for it. Take the money and buy another 750 that isn't so rare. But after saying all this it is your bike and you are free to do with it as you please.