I have a 63, and it was an option. The 4ways were mounted on the bottom of the dash and pulled straight out. It had a red plastic cover that flashed. Can get pics tomorrow if you want. These are still found on ebay and other sites


http://s971.photobucket.com/albums/ae197/jon63c10
1963 c-10 shortbed stepside 427 BBC T16 HD 3 speed
1963 c-10 shortbed fleetside 348 "w" 1st gen big block & powerglide