Here are some pictures of NOS accessory set-ups. These and many other aftermarket set-ups were produced for the early columns. These are absolutely period correct.
http://www.flickr.com/photos/advance-design_parts_co/8129410745/in/set-72157631868452754
Here is the 54 column cup with and without signals, I think you could retrofit this to your column.
http://www.flickr.com/photos/advance-design_parts_co/8129302195/in/set-72157631868452754
http://www.flickr.com/photos/advance-design_parts_co/8129338389/in/set-
72157631868452754
These are now sold as reproductions (classicparts.com).

1950 Chevrolet 3/4-Ton 3600
More pictures on Flickr