I finally tracked down a can of Dolph's EB-41 black insulating varnish. Red, green and clear are easy to find - but nobody carries the black.
I painted the alternator windings. This should hold up better than black spray paint; this stuff is designed specifically to spray copper magnet wire windings.
I stopped at the local Ace Hardware and they had Pony pinch clamps on sale for $1 each; made in USA! They're the orange handled ones.