I showed this in some other thread, but here is an early unrestored March SJ Shelby STILL sporting the over-column brake lines. I cannot vouch for PO changes, but the car has been shown to be mostly unmolested. IMO the 2/1/67 date shown by vendors for the changeover might be based on when Ford wanted to change, not when they did.
Here is a pic of my parts car -- a SJ brake drum car also in the early March time frame within a few thousand of my Shelby's vin also showing over-column brake lines. This brake drum car is where I found the small '3' clip shown earlier.