I did the Eastwood route awhile back ago and it is adequate at best. It is not a true zinc plate and yes, will not accept chromate. I then bought the Caswell kit and has been working wonderfully ever since. Caswell has many colors of chromate, yellow, clear, black and even olive drab. They also have a solution called Zincate which allows you to zinc plate aluminum. Normally you cannot plate aluminum because it oxidizes so quickly. This solution applies a sacrificially coating on it while it is cleaned in mild acid. Works great.
BTW, I know Schvegel plated his BC, which is a frightening thought, and I will give it a good some day. Parts look great.