Wayne,
The parlor car,
Rangeley, at the Maine Narrow Gauge Museum in Portland, ME also has dual brake systems.
I took a bunch of photos of the underside several years ago, but I didn't get a chance to take measurements of the vacuum brake cylinder at the time. Jason or one of the other folks up there could take measurements for replicating the vacuum cylinders; the mounting locations are still obvious under Coach 3, and the brake levers are set up to be able to install brakes on the north truck soon - something else on my to-do list.
Dave Crow