Bill, I do not have the print in front of me but I can look it up come the first of the week if you like, however, the diameter of the pin just does not matter since the 'oversized' area on each end does pass thru the bore of the Spindle Bolt.
Additionally, the 15° forward location (-or 14° in your case) means nothing. This is nothing more than some restorer in modern times establishing an arbitrary number to illustrate their point when describing the desired static position. What DOES matter is the Front Brake Lever should be near-exactly vertical when the brake pedal is fully depressed. This is because that arm has the maximum amount of leverage to push that pin downward against the Brake Operating Wedge. It also does not matter what the static position of the Brake Lever is (-14° forward, or 15° forward, -or whatever #) if the arm goes past straight vertical when the brake is fully depressed. It that brake arm does travel past vertical, then it has the ability to push the pin over against the bore of the spindle.
It is also worth asking if you have verified the brake shoes are centered on the housing plates, -and the tracks, their location, the heads of the pins and the rollers are all within factory specifications. If any of those including tracks are worn or located incorrectly, it has the potential to cause the pin to travel much further distance to energize the shoes which ultimately will cause the Brake Shaft arm on over-rotate.
