That looks a really nice original bike. I agree, don't order anything until you have assessed what is needed. Regarding brakes, yes check the fronts (not just the caliper & m/cyl but the hoses too, I suspect they are the original ones and nearly 50 years old), but also check the rear shoes for the friction material coming away from the metal of the shoes, that's not uncommon & potentially very painful. Carbs seals may actually be ok as it ran not many years ago, I've stored 400s longer than that without needing to replace them. Take the plugs out and oil the bores before running it. Clean the chrome up really carefully, hopefully someone here can suggest a good non-abrasive polish for it. Check the airbox for mouse nests. Best of luck with it.