I would recommend getting new spark plug caps and cables from Z1, while you're replacing ignition stuff. I am not sure about replacing the rectifier. Do a search, there's a writeup somewhere on how to test the rectifier. The regulator can be replaced, but I doubt you'll have to. They can be adjusted, but I don't know that they fail outright. Oregon Motorcycle Parts makes solid state replacements, if you want to go that route. I thought about it and decided not to, since mine's seems fine.
For the carb rubbers, try David Silver Spares. They have the intake rubbers, which are still available from Honda btw, but they also have the airbox to carb rubbers, which I think are a reproduction. These aren't cheap; you may want to consider whether the rubbers are too bad to revive using some of the methods in tricks and tips on this forum.
For the air filter, I bought a UNI foam filter, NU-4055. It's the same shape as the stock item, fits the airbox. I like it because you can clean it. I got mine at Bikebandit, but you can find them at most online stores, and your dealer may have them.
I'm not sure about the fuse block or bulbs, try searching the forums. Also the shop manual may have bulb numbers listed.
Tach and speedo faces, as far as I know, are only available from custom makers. When Motorcycle Classics did their CB500 project, they used Carpy. Try a search for that too and you'll find out where others have bought them.
Good luck!
