Historic Authentication Schemes Before Computers The Bulletin of the Atomic Scientists recently ran an article about an alleged near miss with rockets in 1962, which raises some
interesting cryptographic questions:


  After the usual time-check and weather update came the usual string of
  code.  Normally the first portion of the string did not match the
  numbers the crew had.  But on this occasion, the alphanumeric code
  matched, signaling that a special instruction was to follow. 
  
  Bordne’s crew was instantly alarmed and, indeed, the second part,
  for the first time ever, also matched.
  
  At this point, the launch officer of Bordne's crew, Capt. William
  Bassett, had clearance, to open his pouch.  If the code in the pouch
  matched the third part of the code that had been radioed, the captain
  was instructed to  open an envelope in the pouch that contained
  targeting information and launch keys.


To me it is doubtful that this event ever happened, but it made me wonder how messages were authenticated in pre-computer days during the time of mechanical calculators and long before the advent of public key cryptography.

At this time, the standard was a codebook + superencryption and electromechanical rotor machines. In this case they probably used a code book. Neither scheme provides integrity or authentication.

CBC-MAC as one of the easiest MACs is (barely) feasible to do by hand and doesn't fit the description 'the code in the pouch matched the third part of the message'

Another issue with all of these schemes is that every potential recipient can trivially originate a fraudulent message himself.
There is nothing to keep a rogue crew from opening the secret pouch, constructing a message and sending it out to all other sites.
At that point, all of them will open their pouches, so the seal is useless to find the guilty after the fact.

How were message authentication and integrity handled during the time of codebooks and one time pads? Were there any schemes that provided any non-repudiation capability?

Edit:
I found an article that claims:


  When I served as a Minuteman launch officer in the 1970s, I and
  another crew member could have reverse engineered this entire business
  to create and transmit to the entire U.S. land- and sea-based
  strategic force a fully valid and authentic order that would have been
  carried out by crews whose only validation requirement was to match
  their SAS codes with the order’s SAS codes. (We didn’t use unlock
  codes at the time, even though Defense Secretary McNamara thought
  otherwise). The source of the message was irrelevant; all crews were
  trained to carry out any launch message that validated regardless of
  the source.


But, while somewhat morbidly fascinating, I don't want to dwell solely on the issue of nuclear authentication.
There is a huge body of literature about historical military encryption, but only very little about authentication and integrity. This is strange, because messages were transmitted in error prone Morse code via HF links.
I guess, the famous 'THE WORLD WONDERS' message during the battle of Leyte Gulf shows that at least the Navy did not verify message integrity.
As explained by Cort Ammon, they mostly relied on physical, rather than mathematical processes.

Here is a video on Youtube titled "How to launch a nuclear missile", taken in the Titan Missile Museum mentioned by Cort Ammon.

The message contains a seven character string. 
The personnel in the shelter have a set of envelopes with the first two letters on the outside. 
If the inside of the envelope matches the message, they launch.

Here is another one from a British sub, starting at 23:00. Decryption is done behind a curtain.

It is all very manual, no computer is visible.
Note the wooden club used to protect the codes (24:17).