According to a couple of sites that serial number should be very early production in 1957.
If the gun has no dash in the model number (by the serial when you open the cylinder), then it confirms it was made ca. 1957: the .44 Magnum N-Frame was introduced in '55 but wasn't called the 29 until '57, and the 29-1 change came in 1960. Hope it's in great shape, you've got a classic.
Even Wikipedia articles on S&W models narrow down production ranges by dash designations. Other clues are comparing the actual features present on the gun, looking for dates on the inside of the wood, searching serial number ranges on the web, and finally submitting to the Smith factory for an authentication letter.