Getting hung up on a dwell reading is wasted effort. Set the point gap to the specification the distributor serial number calls for (not the year of the vehicle or the engine), set the spark timing, and drive on. There's no telling how often a stovebolt distributor has been changed over 70 years or so, and not all distributors have the same dwell specification.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!