Temptation is to do cosmetics first................ Don't..............The bike looks ok so go through it and check the electrics, drain and flush the Tank............. It may start with a new battery, (essential),.................. remove and clean the carbs, set tappets and points and timing. If it runs then test charging system and components.
All connections and bullet connectors, switches and earth connections should be taken apart, checked, cleaned and reassembled. This will give you a reliable resistance free loom that will make everything run to its best efficiency. This will also stand you in good steed when/if you build your own harness.
Doing the above, may give you a reliable run about that can have cosmetic work done in-between rides and it gives you a good working knowledge of your bike. When you get around to hacking on it you will appreciate that knowledge because you should be able to trouble shoot any problems after/during the build and the chances are it will run smoothly as all the work has already been done.
All those rust coated acorn nuts and screws and such can be submerged in ordinary household white viniger. Leave for a week and give them rinse with water and a rub with a steelo pad with a bit of wd 40 and they will come up like new.
