Cords With Rumble Seats

Is there a known fiqure of how many Cord Cabriolets were built at the factory with Rumble Seats? I can't find a number in Josh's book Cord Complete.

The following was posted on the HAMB of a Cord Cabriolet with a Rumble Seat claiming it is one of three remaining out of seven built with Rumble Seats;

www.jalopyjournal.com/forum/show ... p?t=759602

I would like to determine if it is a factory built Rumble Seat Cord or if the Rumble Seat was added at a later date.

Thanks