My buddy had a '71 Cougar with sequentials. They make use of a box (6" x 10" x 2"?) that mounts in the trunk. Wires go in, wires go out, lights work sequentially.
Like the late 60s Cougars, the Shelby Mustangs also had sequentials. You might not want brand F on your 'bolt, but there are probably plenty of replacement boxes for those models and could easily be used for your application. Off the top of my head, I'd try Larry's Mustang.
Bill
