I'm also considering including a dual-master cylinder setup from Turner for my '57 Golden Hawk restoration. Two questions:
1) how do you check and refill these, since the little hole in the floor-pan was designed around the original single-cylinder unit? Is there enough access? (I don't like the idea of cutting a larger opening in the floor....)
2) I know there are never guarentees, not asking for one, but with a total system replacement (cylinders, lines, hoses, shoes, and master) has anyone ever heard of a brake "system" failure that a dual-master would have prevented? Isn't the only "safety enhancement" to protect against a busted hose or cylinder seal failure that drains your fluid so quickly that pressure is lost to all four cylinders and thus 'no brakes'? I am trying to keep things original, and don't mind updates where they make a lot of sense (adding seat-belts, but, for example, am NOT going to disc brakes), so I have mixed feelings about the dual-master. Also, I can get a stainless-lined single-cylinder, but not sure about a 'new' master, I know the Turner unit is NOT stainless (I asked him).
Thoughts? Experiences to share on the subject?